NOTE: This YRM applies to different model years of the GM 4.3 liter, V-6 engine. While there can be physical differences in the parts, many of the procedures will apply to all of the models. If the different parts require separate procedures, all the procedures will be given. 
CAUTIONChanges to the engines have occurred at each model year. Do not install parts from one model year engine into another model year engine. Installation of the wrong parts will cause poor performance, wear, and failure of the engine.
CAUTION Disconnect the battery cables before doing any disassembly and repair of the engine or parts of the electrical system.
The diodes and resistors in the electrical system can be damaged if the following cautions are not followed:
• Do not disconnect the battery when the engine is running. The voltage surge can damage the diodes and resistors.
• Do not disconnect an electric wire before the engine is stopped and the switches are OFF.
• Do not cause a short circuit by connection of the electric wires to the wrong terminals. Make sure a correct identification of the wire is made before it is connected.
• Make sure a battery is the correct voltage and polarity before it is connected.
• Do not check for current flow by making a spark because the electronic components can be damaged.
This YRM has the description and the repair instructions for the GM 4.3 liter, V-6 engine. Checks and Adjustments, Troubleshooting procedures, and Specifications are also included. The cylinder block is made of cast iron. The arrangement of the cylinders is in a V shape, with three cylinders on each bank. From the front, cylinders on the right bank are numbered 1, 3, and 5 and cylinders on the left bank are numbered 2, 4, and 6. The cylinder heads are cast iron and have one intake valve and one exhaust valve for each cylinder. A spark plug is located between the valves in the side of the cylinder head. The valve guides and seats are integral to the cylinder head.
The crankshaft is supported by four main bearings. The number four bearing at the rear of the engine is the end thrust bearing. The bearings are retained by bearing caps that are matched with the block for proper alignment and clearances.
The camshaft is steel and is supported by four bearings pressed into the engine block. The camshaft is driven by a chain from the crankshaft. A spiral gear machined into the camshaft near the rear journal drives a shaft assembly which operates the oil pump drive shaft assembly.
The pistons are made of cast aluminum and have two compression rings and one oil control ring assembly. The piston
is a low-friction, lightweight design with a flat top and barrel-shaped skirt. The piston pins are offset to reduce piston slap. They have a floating fit in the piston and are retained by a press fit in the connecting rod. The connecting rods are forged steel and are machined with the rod cap installed for proper clearances and alignment.
The balance shaft is cast iron and mounted in the crankcase above and in-line with the camshaft. The balance shaft is driven by a gear from the camshaft.
The valve mechanism is actuated by push rods and rocker arms from the camshaft. The rocker arm pivots on a ball to open the valve. Later model engines have hydraulic valve lifters that keep all parts of the valve train in constant contact. Each lifter acts as an automatic adjuster and maintains zero lash in the valve train, eliminating the need for periodic valve adjustment.
When the engine has a gasoline fuel system, it has electronic fuel injection with an electronic engine control system. When the engine has a LPG fuel system, it uses an LPG carburetor with the Microprocessor Spark Timing System (MSTS). Engine Removal and Installation The Removal and Installation procedures for the engine are in the Frame section for each model of lift truck. See the Transmission sections to separate the transmission from the engine. 
WARNINGDisconnect the battery cables before making repairs to the engine.
1. Drain cooling system.
2. Disconnect and remove coolant hose from housing for thermostat.
3. Remove air cleaner, distributor, throttle body, intake manifold, and exhaust manifolds. Remove drive belt(s) and remove brackets for drive belt tensioner and alternator.
4. Remove spark plugs.
5. Remove rocker arm cover. See Figure 1. NOTE: For year 2002 or later model engines, go to Step 10. 6. Remove nuts and balls for rocker arms. Remove rocker arms and push rods. Keep parts for each rocker arm assembly together. Mark assemblies so they can be installed in their original positions.
7. Remove rocker arm studs.
8. Remove capscrews that hold cylinder head to block. Remove capscrews in the reverse order of the tightening sequence shown in Figure 12. Remove cylinder head and gasket. 9. Use a valve spring compressor and remove valve stem keys, caps, springs, and oil seals. Discard oil seals. Remove valves. Organize valves and springs so they can be installed in their original positions.
10. Remove valve rocker arms. See Figure 2. 11. Remove valve rocker arm supports.
12. Remove valve push rods.
1. Rocker Cover 2. Nut 3. Ball 4. Rocker Arm |
5. Cylinder Head 6. Head Gasket 7. Gasket |
Figure 1. Cylinder Head
1. Clean carbon from valve ports and combustion chambers in cylinder head.
2. Clean carbon and oil from valves, push rods, and rocker arms.
3. Clean valve guides.
4. Clean surfaces of cylinder head where gaskets fit.
5. Inspect cylinder head for cracks in ports, combustion chambers, and external surfaces.
6. Measure cylinder head for warping with a straight edge and feeler gauge. Refer to Engine Specifications for tolerances. 1. Valve Rocker Arm
2. Valve Rocker Arm Support
3. Push rod
Figure 2. Remove Valve Rocker Arm and Push Rod (Year 2002 or Later Engine Models)
7. Inspect valves for burned or damaged areas in seat surfaces. Inspect for cracks and damaged or worn valve stems. Valve stems with excessive guide clearance must be repaired or replaced. Refer to Engine Specifications. Valve Guides and Seats, Repairs Measure the clearance between the valve stem and the guide as shown in Figure 3. See Engine Specifications for maximum clearances. If the clearance is more than the maximum amount, oversize valves or new valve guides must be installed. Use a reamer of the correct size when installing new valve guides. Use normal service procedures when grinding the valve seats. See the Engine Specifications for dimensions. NOTE: Before any work is performed on the valve faces and seats, make sure the clearance of the valve stems in their valve guides is within specifications.
A correction for minimum wear and damage to the valve and seat can be done by a process called lapping. When the valve seats are lapped, keep the valve faces and seats within the specifications. Make sure all of the lapping compound is removed from the valve and valve seat when the process is completed.
Valves with minor pits in the valve faces can be machined to the proper angle. There are many different types of equipment for repairing valve faces. Follow the instructions of the manufacturer of the equipment that you are using. Valves must be machined to the proper specifications. See Figure 4. 1. Valve Stem
2. Dial Indicator
Figure 3. Valve Steam Clearance
NOTE: Seat width dimension applies to the 46° face only.
1. Cylinder Head
Figure 4. Valve Seat Specifications for Inlet and Exhaust Valves
Replace a valve if any of the following conditions are present:
• Valve stem is worn below specifications.
• Valve stem is bent.
• Valve face is warped.
• Any part of the valve is cracked.
• Any wear or damage to the valve face that cannot be removed by resurfacing and still meet the specifications shown in Figure 5.
Figure 5. Valve Head Measurements
NOTE: Before any work is done on the valve faces and seats, make sure the clearance of the valve stems in their valve guides is within specifications.
CAUTION The exhaust valve seats in these cylinder heads are induction-hardened. Removal of too much valve seat material will damage the valve seats which will require replacement of the cylinder head.
Damaged valve seats can be resurfaced with a tool that is designed to repair valve seats. There are many different types of equipment for repairing valve seats. Follow the instructions of the manufacturer of the equipment that you are using.
The valve seats are ground at three different angles: 30°, 46°, and 60°. This method makes a valve seat that is the proper width and produces the correct contact line between the valve and valve seat. The specifications for the valve seats are shown in the Engine Specifications section and in Figure 4. • If the contact line is too high, it can be made lower by using a 30° stone.
• If the contact line is too low, it can be raised using the 46° stone.
• If the seat is too narrow, it can be made wider using a 46° stone.
• If the seat is too wide, it can be made narrower using a 60° stone.
The correct dimensions for the valve seat widths and valve/valve seat overlap are shown in Figure 6. The valve seat widths are the dimensions of the 46° face only. The valve/valve seat overlap is the distance from the edge of the seat to the outside edge of the valve. Measure the length of the valve springs. The correct length is 51.6 mm (2.03 in.).
WARNING Be careful when testing the valve springs. These springs can come loose with enough force to cause an injury. Always use equipment that was designed to test springs. Always wear eye and face protection while testing valve springs.
Use a special tool to check the tension of the valve springs. Compress the spring to the correct height and check the tension. For the correct specifications, see Figure 7. Replace valve springs that are not within specifications. A. Exhaust Valve
B. Inlet Valve
1. Cylinder Head
2. Valve
Figure 6. Valve Seat Widths and Valve/Valve Seat Overlap
Figure 7. Valve Spring Specifications
Legend for Figure 7
A. Variation from Vertical: less than 1.6 mm (0.063 in.)
B. Free Length: 51.6 mm (2.03 in.)
C. Spring Compressed to 338 to 374 N (76 to 84 lbf) at 43 mm (1.69 in.)
D. Installed Height
Early Models : 42.92 to 43.43 mm (1.690 to 1.710 in.)
Late Models:
Intake: 45.2 mm (1.78 in.)
Exhaust: 45.2 to 43.43 mm (1.780 to 1.710 in.)
Rocker Arm Studs (Early Models) These studs are pressed into the head.
Replace a stud that has damaged threads or is loose in the cylinder head. New studs are available in the following oversizes: 0.003 in. and 0.013 in.
1. To remove old stud, install spacer, flat washer, and nut to damaged stud. Use a wrench to remove damaged stud. See Figure 8. CAUTION Do not attempt to install an oversized stud without reaming the stud hole to the new size. Installation of an oversized stud without reaming the stud hole can cause cracks in the cylinder head.
2. Use a reamer of the correct size for new oversized stud. Apply SAE 90 lubricant to new stud during installation. Install new stud as shown in Figure 9. NOTE: Early models only.
Figure 8. Rocker Arm Stud Removal
Rocker Arm Studs (Late Models) WARNING DO NOT remove a stud from the cylinder head when the engine is hot. Some of the studs fit into coolant passages and can release pressure and hot coolant when removed. The steam and boiling coolant can cause burns.
CAUTION Disposal of lubricants and fluids must meet local environmental regulations.
Drain the cooling system before replacing the studs. The studs for late model engines have threads that hold them to the cylinder head. See Figure 10. A stud that has damaged threads must be replaced with a new stud. If the threads in the head are damaged, a thread repair kit can be used. If the damaged threads cannot be repaired with a thread repair kit, then the head must be replaced. NOTE: Early models only.
Figure 9. Rocker Arm Stud Installation
NOTE: Late models only.
1. Stud
Figure 10. Studs With Threads
1. Install each valve in correct port. Install oil seal in lower groove. Install shim, damper, spring, shield, and cap or rotator. Using a spring compressor, compress assembly and install retainers. Measure height of valve spring as shown in Figure 11. Measure from top of shim to top of retainer cap. Install shims to get correct height shown in Figure 11. The installed height of valve spring must not be less than minimum height. 2. Clean surface of cylinder head and top of cylinder block. Make sure threads in block are clean.
3. Install cylinder head gasket and cylinder head. Make sure cylinder head is aligned with pins in block.
4. Use a sealant on threads of capscrews for cylinder head. Install capscrews as follows:
a. On 1995 and earlier engines, tighten capscrews in three steps. Tighten all capscrews to one torque specification, then use the next specification: 34 N•m (25 lbf ft), 61 N•m (45 lbf ft), and 90 N•m (65 lbf ft). Use sequence shown in Figure 12. b. On 1996 model and later engines, tighten all capscrews to 30 N•m (22 lbf ft). Use sequence shown in Figure 12. Next, tighten capscrews 11, 7, 3, 2, 6, 10 an additional 55 degrees. Tighten capscrews 12 and 13 an additional 65 degrees. Tighten capscrews 1, 4, 8, 5, 9 an additional 75 degrees. A. Variation from Vertical: less than 1.6 mm (0.063 in.)
B. Free Length: 51.6 mm (2.03 in.)
C. Spring Compressed to 338 to 374 N (76 to 84 lbf) at 43 mm (1.69 in.)
D. Installed Height
Early Models : 42.92 to 43.43 mm (1.780 to 1.710 in.)
Late Models:
Intake: 45.2 mm (1.78 in.)
Exhaust: 45.2 to 43.43 mm (1.690 to 1.710 in.)
Figure 11. Valve Spring Specifications
A. Fan End
Figure 12. Cylinder Head Tightening Sequence
5. Apply RTV sealant (Yale part number 520039889) to front and rear surfaces between intake manifold and engine block. See Figure 13. The bead of sealant must be 5 mm (0.2 in.) thick and extend up sides of heads 13 mm (0.5 in.) to seal and retain gaskets. 1. Extend bead 13 mm (0.5 in.) up heads (front and rear).
2. Rear
3. Front
Figure 13. Intake Manifold Sealant Locations
6. Install gaskets and intake manifold. Tighten capscrews in sequence shown in Figure 14. Tighten capscrews on early models to 48 N•m (35 lbf ft). On later models tighten capscrews on first pass to 3 N•m (27 lbf in). Tighten capscrews on second pass to 12 N•m (106 lbf in). Tighten capscrews on final pass to 15 N•m (133 lbf in). NOTE: For year 2002 or later model engines, perform Step 8 through Step 18. For 2001 and earlier model engines, perform Step 7 and Step 14 through Step 18. NOTE: Install parts as marked during removal.
8. Install valve push rods. See Figure 15.
A. Early Models B. Late Models |
Figure 14. Inlet Manifold Tightening Sequence
Figure 15. Install Valve Push Rod CAUTION Be sure that the arrow on the valve rocker arm support is in the up position. See Figure 16. 9. Install valve rocker arm supports.
Figure 16. Install Valve Rocker Arm Supports
10. Apply a molybdenum grease or equivalent to the following valve rocker arm contact surfaces: See Figure 17. • Valve push rod socket
• Roller pivot
• Valve stem tip
11. See Figure 18. Install the valve rocker arm assemblies as follows: a. Finger start the rocker arm bolt at location 1 in Figure 18. b. Finger start the rocker arm bolt at location 2 in Figure 18. c. Finger start the rocker arm bolt at location 3 in Figure 18. d. Finger start the remaining three valve rocker arm bolts.
12. Rotate the crankshaft balancer to position the crankshaft balancer alignment mark 57 to 63 degrees clockwise or counterclockwise from the engine front cover alignment tab. See Figure 19. 1. Valve Push rod Socket
2. Roller Pivot
3. Valve Stem Tip
4. Rocker Arm Bolt
Figure 17. Lubricate Valve Rocker Arm Surfaces
1. Bolt At Location 1
2. Bolt At Location 2
3. Bolt At Location 3
Figure 18. Install Valve Rocker Arm Assemblies
1. Crankshaft Balancer Alignment Mark
2. Engine Front Cover Alignment Tab
Figure 19. Rotate Crankshaft Balancer
NOTE: Once the valve rocker arm assemblies are installed and properly torqued, no additional valve lash adjustment is required.
13. Tighten the valve rocker arm bolts to 30 N•m (22 lbf ft). See Figure 17. 14. Use new gasket and install valve covers. Tighten capscrews to 12 N•m (107 lbf in). 15. Install spark plugs.
16. Install throttle body, air cleaner, and distributor. Install brackets for drive belt tensioner and alternator. Install drive belt(s).
17. Install exhaust manifolds. Tighten capscrews in two steps; first to 15 N•m (133 lbf in), then to 31 N•m (274 lbf in). If used, bend lock tabs against heads of capscrews.
18. Install coolant hose to housing for thermostat. Fill coolant system with coolant. See the Periodic Maintenance section for your lift truck. Cylinder Block Cleaning and Inspection WARNING Cleaning solvents can be flammable and toxic and can cause skin irritation. When using cleaning solvents, always follow the solvent manufacturer’s recommended safety procedures.
WARNING Compressed air can move particles so they cause injury to the user or to other personnel. Make sure the path of the compressed air is away from all personnel. Wear protective goggles or a face shield to prevent injury to the eyes.
After the engine is disassembled, clean cylinder block in solvent and dry with compressed air. Make sure all oil passages are clean. Remove gaskets from surface of block.
Inspect bores for pistons for wear or damage. Measure bores and check dimensions shown in Engine Specifications. Repair cylinder block, as necessary. NOTE: It is important that the piston bores are prepared correctly before new piston rings are installed. Incorrect preparation can cause the parts to wear quickly. Use a hone in the piston bores when installing new rings. Use the hone as follows:
1. Use a hone with a 280-grit stone. Make sure stone is clean and will not damage bore.
2. Move hone quickly (approximately 60 times per minute) up and down in bore. Make sure hone makes a cross pattern of 45 to 60 degrees. Use hone until entire length of bore has this pattern.
3. After using the hone, clean cylinder block with hot water and detergent. Make sure all metal particles are removed from block. Dry bores and lubricate them with engine oil. Engine Mounts Installation If the engine mount was removed from the cylinder block, install and tighten capscrews for mount as follows.
GC/GLC070-120LG/MG
GP/GLP/GDP070-110LG/MG |
31 N•m (23 lbf ft) |
GLC60-70CA (GC/GLC/GDC135-155CA)
GDP60-70CA (GP/GLP/GDP135-155CA) |
50 N•m (37 lbf ft) |
GLP/GDP35-50LJ/MJ (GP/GLP/GDP070-120LJ/MJ) |
52 N•m (38 lbf ft) |
Lubrication System Repair Oil Pump, Remove and Disassemble 1. Remove oil sump.
2. Remove capscrew at mount for pump. Remove oil pump and shaft. See Figure 20. 3. Remove cover for oil pump. Put marks on gear teeth to show their correct location during assembly.
4. Do not remove tube and screen assembly unless it is damaged. The tube and screen must be replaced as an assembly.
5. Remove retaining pin, pressure regulator spring, and pressure regulator valve from pump cover.
1. Capscrew 2. Screen 3. Driven Gear 4. Drive Gear 5. Retainer 6. Shaft |
7. Housing 8. Spring 9. Relief Valve 10. Cover 11. Pin |
Figure 20. Oil Pump
WARNING Cleaning solvents can be flammable and toxic and can cause skin irritation. When using cleaning solvents, always follow the solvent manufacturer’s recommended safety procedures.
WARNING Compressed air can move particles so they cause injury to the user or to other personnel. Make sure the path of the compressed air is away from all personnel. Wear protective goggles or a face shield to prevent injury to the eyes.
Clean parts of oil pump in solvent and dry with compressed air. Inspect gears, shaft, and body of pump for wear or damage.
Oil Pump, Assemble and Install NOTE: There are some variations in the oil pumps installed during the years of manufacture of these engines, but the design is the same. The repair procedures are the same. See the Parts Manual for each oil pump.
1. Install NEW pressure regulator valve and spring into pump cover. Install retaining pin.
2. Install gears in body of pump. Make sure to align identification marks. Install cover for oil pump and tighten capscrews to 12 N•m (106 lbf in). Turn shaft for oil pump and check for smooth operation.
3. Use a sealant when replacement of tube and screen assembly is necessary. The tube and screen assembly must have a good press fit into the oil pump body. Do not damage tube during installation. Make sure surface of screen assembly is parallel to bottom surface of cylinder block. See Figure 21. 4. Install oil pump shaft and NEW retainer.
5. Install oil pump assembly to engine. Make sure shaft is aligned with slot in distributor shaft. On early models (1995 and older engines), tighten capscrew at mount to 47 N•m (35 lbf ft). On late models (1996 and later), tighten capscrew to 90 N•m (66 lbf ft).
Figure 21. Oil Pump Tube and Screen Installation
1. Install oil sump on early models (1995 and earlier engines) as follows:
a. Install new gasket(s) and oil sump. See Figure 22. Use a sealant on gasket(s) in the following locations: at front cover to block joint and rear seal retainer to block joint. The sealant must extend 25 mm (1 in.) in both directions at each of the four corners. Figure 22. Oil Sump
Legend for Figure 22
A. Early Models B. Late Models |
b. Tighten capscrews for oil sump as follows: 1/4-20 capscrews, 10 N•m (89 lbf in); 5/16-18 capscrews, 19 N•m (168 lbf in).
2. Install oil sump on late models (1996 and later engines) as follows:
a. Apply an RTV sealant to surfaces of engine block as shown in Figure 23. A. Fan End
Figure 23. Oil Sump Installation
b. Install gasket and oil sump. Make sure vertical surfaces at back of engine block and oil sump are even.
c. Tighten capscrews and nuts for oil sump in sequence shown in Figure 24 to 25 N•m (221 lbf in). Figure 24. Oil Sump Installation Timing Cover, Timing Sprockets, Camshaft, and Valve Lifters NOTE: For model GLP/GDP35-50LJ/MJ (GP/GLP/GDP070-120LJ/MJ), refer to the section Cooling System 700 YRM 740.
1. Remove fan assembly and belts.
2. Remove crankshaft pulley and vibration damper. See Figure 25. Use a tool that pulls on center of vibration damper. Do not pull on outside diameter of vibration damper.
1. Timing Cover 2. Vibration Damper |
3. Tool for Removing Vibration Damper |
Figure 25. Timing Cover
3. Remove crankshaft position sensor from timing cover. See Figure 26. 4. Remove capscrews and stud for timing cover. Remove timing cover from engine. See Figure 27. 5. Remove crankshaft position sensor reluctor ring from crankshaft. See Figure 28. NOTE: The plastic timing cover can be used only once. When the engine has a plastic timing cover, always install a new one.
1. Install crankcase position sensor reluctor ring on crankshaft. See Figure 28. Make sure open side of seal is toward inside of cover. 2. Use a sealant on sump gasket in the following locations: at front cover to block joint and rear seal retainer to block joint. The sealant must extend 25 mm (1 in.) in both directions at each of the four corners. During installation of the cover, use a special tool to align oil seal with crankshaft. The vibration damper will damage the oil seal if it is not installed correctly. Tighten capscrews for cover to 12 N•m (106 lbf in). See Figure 27. 3. Install crankshaft position sensor. Tighten crankshaft position sensor bolt to 8 N•m (71 lbf in). See Figure 26. 4. Lubricate lips of seal with clean engine oil before vibration dampener is installed. Use a special tool to pull vibration damper onto crankshaft. See Figure 29. Tighten capscrew for damper to 95 N•m (70 lbf ft). 5. Install crankshaft pulley, belts, and fan assembly.
1. Crankshaft Position Sensor Bolt
2. Crankshaft Position Sensor
3. Timing Cover
Figure 26. Crankshaft Position Sensor
Figure 27. Timing Cover
1. Crankshaft Position Sensor Reluctor Ring
2. Crankshaft
Figure 28. Crankshaft Position Sensor Reluctor Ring
Figure 29. Timing Cover
1. Remove timing cover. On late models, remove ring for crankshaft position sensor. See Figure 30. 2. Check timing chain for wear. If timing chain can be moved back and forth more than 16 mm (0.63 in.), install a new chain.
1. Timing Marks 2. Timing Chain |
Figure 30. Timing Marks
3. Remove capscrews for camshaft sprocket. Use a puller to remove crankshaft sprocket. Make sure timing chain is removed with sprockets.
1. Install crankshaft sprocket. Install timing chain on camshaft sprocket. Install camshaft sprocket with chain. Make sure marks are aligned as shown in Figure 30. The number 4 cylinder will be at top dead center (TDC) on the compression stroke. Tighten capscrews to camshaft sprocket to 28 N•m (21 lbf ft). On late models, install ring for crankshaft position sensor. 2. Lubricate chain and sprockets with new engine oil. Install timing cover as described in section for Timing Cover. 1. Remove intake manifold, push rods, lifter guides, and valve lifters.
2. Remove timing cover as described in section Timing Cover. Align timing marks. Remove timing chain, sprockets, and camshaft retainer. 3. Install two or three 5/16-18 capscrews that are 100 to 125 mm (4 to 5 in.) long into camshaft. See Figure 31. These capscrews will make the camshaft easier to control. Carefully remove camshaft from cylinder block. All camshaft bearings are the same size. Do not damage bearings or camshaft during removal. 4. If necessary, use a special tool as shown in Figure 32 to remove camshaft bearings. Remove front and rear bearings last. Inspect entire camshaft for any signs of wear or damage. Measure diameter of each bearing surface on camshaft. Do the measurement at different positions on the surface of the bearing to see if they are round. If the difference of the readings for each bearing is more than 0.025 mm (0.001 in.), replace camshaft. Check for a bent camshaft or excessive camshaft runout. If runout exceeds 0.065 mm (0.0026 in.), the camshaft is bent and should be replaced.
NOTE: Late model shown, other models similar.
Figure 31. Camshaft
1. Tool for Camshaft Bearings
Figure 32. Camshaft Bearings
1. Use a special tool as shown in Figure 32 to install camshaft bearings. See Figure 33. Install front and rear bearings first. Make sure oil holes in bearings are aligned with oil holes in block. Use a sealant on rear camshaft plug and install plug in block. Make sure plug is even with or 0.80 mm (0.03 in.) below surface of block. 2. Lubricate camshaft lobes with a molybdenum lubricant. Lubricate camshaft bearings with engine oil. Install two or three 5/16-18 capscrews that are 100 to 125 mm (4 to 5 in.) long into camshaft. See Figure 31. These capscrews will make camshaft easier to control. Carefully install camshaft in cylinder block. 3. Lubricate and install retainer for camshaft. Tighten capscrews to 14 N•m (125 lbf in).
4. Install gear for the balance shaft as described in procedures for Balance Shaft. Figure 33. Camshaft and Retainer
5. Install timing sprockets, chain, and cover as described in procedures for Timing Cover. 1. Remove intake manifold.
2. Remove retainer for lifters.
3. Remove timing cover as described in section Timing Cover. Remove timing chain and sprocket from camshaft. 4. Remove driven gear from balance shaft. Remove retainer. See Figure 34. 5. Use a soft-faced hammer to remove balance shaft. See Figure 35. NOTE: The balance shaft and front bearing are serviced as a unit.
6. Use a special tool to remove rear bearing.
1. Sprocket, Camshaft 2. Drive Gear, Camshaft |
3. Driven Gear, Balance Shaft 4. Balance Shaft 5. Retainer |
Figure 34. Balance Shaft Components
A. Front
Figure 35. Balance Shaft Removal
1. Lubricate rear bearing with new engine oil. Use a special tool to push rear bearing into block. See Figure 34 and Figure 36. A. Front
Figure 36. Balance Shaft Installation
2. Lubricate front bearing with new engine oil. Use a driver to install balance shaft into engine block.
3. Install retainer for balance shaft. Tighten screws for retainer to 14 N•m (125 lbf in).
4. Install driven gear onto balance shaft. Tighten bolt to 20 N•m (177 lbf in), plus an additional 35 degrees of rotation. Rotate balance shaft by hand to make sure there is clearance between retainer and shaft. If the balance shaft does not rotate freely, check that retaining ring on the front bearing is in its seat.
5. Temporarily install drive gear on camshaft. Turn camshaft until timing mark on drive gear is straight up. Remove drive gear and rotate balance shaft until mark on driven gear is straight down. Install drive gear on camshaft. Make sure timing marks are in the position shown in Figure 37. 6. Install timing chain and sprocket on camshaft. Make sure timing marks are in the position shown in Figure 30. Tighten capscrews that attach sprocket to camshaft to 28 N•m (21 lbf ft). 7. Install timing cover as described in section Timing Cover. 1. Alignment of Timing Marks
2. Driven Gear, Balance Shaft
3. Drive Gear, Camshaft
Figure 37. Balance Shaft Timing Marks
8. Make sure all lifters and guides for lifters are properly installed. Install retainer for lifters. Tighten bolts for retainer to 16 N•m (142 lbf in).
1. The hydraulic valve lifters normally do not need repair unless they become dirty, causing them to malfunction or the roller does not operate properly. The hydraulic valve lifters must be clean to operate correctly. If a hydraulic valve lifter must be disassembled, make sure small parts are handled carefully to prevent loss or damage.
2. Remove air bonnet, distributor, and intake manifold.
4. Remove hydraulic valve lifters. Put lifters in a rack so they can be installed in their original positions.
CAUTION The internal parts of a lifter are a precise fit to each lifter body. When servicing the lifters, make sure the parts from one lifter are not mixed with another lifter. If any part of the lifter or roller is worn or damaged, the lifter must be replaced.
1. Hold plunger down with a push rod. See Figure 38. Use blade of a small screwdriver to remove retainer for push rod seat.
1. Check Ball Assembly 2. Plunger 3. Metering Valve 4. Push Rod Seat |
5. Retainer 6. Spring 7. Lifter Body 8. Retainer |
Figure 38. Hydraulic Valve Lifter
2. Remove push rod seat and metering valve.
3. Remove plunger, check ball assembly, and plunger spring.
4. Use a small screwdriver as a pry bar to remove check ball retainer from plunger. See Figure 39. Figure 39. Check Ball Assembly Removal
Clean all parts in a cleaning solvent and inspect them carefully. If any parts are damaged or worn, the complete hydraulic valve lifter must be replaced. If the body of the hydraulic valve lifter is worn, also inspect bore in cylinder block. If roller of hydraulic valve lifter is worn or damaged, inspect camshaft lobe for wear and damage.
1. Assemble check ball assembly. Put check ball on small hole in bottom of plunger. Install check ball spring in seat of check ball retainer. Put check ball retainer over check ball so check ball spring is on check ball. Carefully press check ball retainer into position in plunger. See Figure 40. 2. Put plunger spring over check ball retainer and slide lifter body over spring and plunger. See Figure 38. 3. Fill assembly with SAE 10 engine oil. Put a 3 mm (0.125 in.) drift into plunger and push plunger until holes for oil are aligned. See Figure 41. Now put a 1.6 mm (0.0625 in.) drift through holes to hold plunger. Remove 3 mm (0.125 in.) drift and fill assembly again with SAE 10 oil. Figure 40. Check Ball Assembly Installation
1. 3 mm (0.120 in.) Drift Pin 2. Oil Feed Hole |
3. 1.6 mm (0.063 in.) Pin |
Figure 41. Hydraulic Valve Lifter Assembly
4. Install metering valve and push rod seat. See Figure 38. Install retainer for push rod seat. Push down push rod seat to loosen 1.6 mm (0.063 in.) drift and remove drift. The hydraulic valve lifter is now ready for installation. 1. Lubricate all roller and lifter surfaces with new engine oil. Install lifters in their original positions. Make sure guides are in correct positions. See Figure 42. 2. Install retainer. Tighten capscrews to 16 N•m (142 lbf in).
4. Install intake manifold and distributor.
1. Rocker Arm 2. Cylinder Head 3. Cylinder Block 4. Camshaft |
5. Lifter 6. Retainer 7. Guide 8. Push Rod |
1. Remove oil pan, oil pump, and flywheel. Remove rear seal retainer (late models).
3. Mark caps for connecting rods so they can be installed in their correct locations. Remove caps and bearing inserts for connecting rods. Make sure all parts from each rod assembly remain together.
4. Mark caps for main bearings so they can be installed in their correct locations. Remove caps for main bearings. Make sure all parts from each bearing assembly remain together.
5. Remove crankshaft with extreme care to prevent damage to journals and thrust flanges of crankshaft.
WARNING Commercial cleaning solvents can be flammable and toxic and can cause severe skin irritation. When using commercial cleaning solvents, always comply with the solvent manufacturer’s recommended safety precautions.
Compressed air can move particles so they cause injury to the user or to other personnel. Make sure the path of the compressed air is away from all personnel. Wear protective goggles or a face shield to prevent injury to the eyes.
1. Clean crankshaft with solvent and dry it with compressed air. Make sure oil passages are not plugged.
2. Inspect crankshaft for cracks or other damage.
3. Inspect bearing journals and thrust surfaces for scratches or damage caused by a lack of lubrication.
4. Inspect crankshaft for wear and damage. See Figure 43. Use a micrometer to measure journals for bearings of crankshaft. Do measurement at different positions to see if the surface of the bearing is round. The correct sizes are given in the Engine Specifications section. Figure 43. Crankshaft Inspection
5. If crankshaft journals must be repaired, they can be ground to the following diameters smaller (undersize) than the original size:
0.254 mm (0.010 in.)
0.508 mm (0.020 in.)
NOTES ABOUT MAIN BEARINGS: Main bearings are an insert bearing that do not use shims for adjustment. Main bearings are available in a standard size and the following undersizes: 0.0254 mm (0.001 in.), 0.0508 mm (0.002 in.), 0.2286 mm (0.009 in.), 0.254 mm (0.010 in.), and 0.508 mm (0.020 in.). If a bearing on a journal is worn, both the upper and lower half of the bearing must be replaced.
When the crankshaft is assembled by the manufacturer, the main bearings are specially selected to obtain close tolerances. For this reason, you can find one-half of a standard size insert with one-half of a 0.0254 mm (0.001 in.) undersize insert. This combination will decrease the clearance 0.0127 mm (0.0005 in.) from using a full standard bearing.
When a production crankshaft cannot be fitted with this method, the main journal is then ground 0.2286 mm (0.009 in.) undersize. Only those main bearing journals that cannot be fitted with standard, 0.0254 mm (0.001 in.), or 0.0508 mm (0.002 in.) undersize main bearing will be ground. A 0.2286 mm (0.009 in.) and a 0.254 mm (0.010 in.) undersize bearings will be selected as described to obtain close tolerances.
A production crankshaft that has been ground will have the following identification:
• The crankshaft journal that has been ground will have a 9 marked in the metal of the crankshaft next to the journal. A spot of light green paint is also added to the crankshaft.
• The main bearing cap is also marked with green paint.
How to Check Clearance Between Main Bearings and Their Journals 1. Use Plastigage® or equivalent to check clearance. The procedure is similar for both connecting rod bearings and main bearings. If engine has been removed from lift truck, put engine so crankshaft is up. The weight
of the crankshaft is against the upper bearing half and the total clearance can be measured correctly. If the engine is still in the lift truck, the crankshaft must have a support to remove any additional clearance between the upper bearing half and its journal.
2. All main bearing caps must be installed and their capscrews tightened to the specifications.
3. Check rear main bearing first. Remove cap for rear main bearing. The procedure for checking the clearance of the other bearings is similar.
4. Clean oil from bearing half and journal to be checked. Put a piece of Plastigage across full width of bearing journal as shown in Plastigage® on Bearing Journal. Do not rotate crankshaft when Plastigage is between main bearing and its journal. 5. Install main bearing cap and tighten capscrews. See Torque Specifications. The capscrews must be tightened to their final torque or there will be an error in the measurement. 6. Remove main bearing cap. The Plastigage® will be compressed and wider and will adhere to either the bearing or its journal. Use scale on envelope for Plastigage® to measure width of plastic at its widest point. The scale will indicate the clearance in millimeters or thousandths of an inch. See Figure 47. 7. If the clearance is greater than the specifications, select a new undersize bearing set and install it. Measure clearance again. If clearance cannot meet specifications with the available undersize bearings, bearing journal must be ground to a new undersize. If bearing journal is already at maximum undersize, crankshaft must be replaced.
8. If clearance is within specifications, lubricate bearing with engine oil and install main bearing and bearing cap. Tighten capscrews on main bearing cap to correct specifications.
9. Turn crankshaft to make sure it rotates smoothly.
10. Check axial clearance between rear main bearing and thrust surface. Push crankshaft forward. See Figure 44. Measure clearance between crankshaft and thrust surface of rear bearing. See Engine Specifications for correct clearances. A. Fan End
1. Measure Clearance
Figure 44. Measuring Crankshaft Axial Clearance
1. On engines with a two-piece rear seal, install seal halves so lips are toward fan end of engine. Apply sealant to ends of seal halves. Apply engine oil to seal during installation. Do not get any oil on ends of seal.
NOTE: With the use of special tools, the main bearings and the rear crankshaft seal (two-piece) can be replaced without removing the crankshaft.
2. Install main bearings in cylinder block and bearing caps. Lubricate bearings with engine oil and carefully install crankshaft in cylinder block.
3. Install bearing caps. Make sure arrows on bearing caps are toward front (fan end) of engine. Push crankshaft forward and measure clearance at front side of rear main bearing. The correct clearance is 0.050 to 0.20 mm (0.002 to 0.008 in.). See Figure 44. 4. Tighten capscrews for bearing caps to 70 N•m (52 lbf ft). Move crankshaft forward and backward to align rear main bearing. Tighten capscrews for all bearing caps to 106 N•m (78 lbf ft). On late model engines, tighten capscrews for bearing caps to 20 N•m (177 lbf in) on the first pass. Move crankshaft forward and backward to align rear main bearing. Tighten capscrews for all bearing caps an additional 73 degrees on the final pass.
5. Install connecting rods, oil pump, and oil pan. Install flywheel and other parts.
6. On late model engines with a one-piece seal, install seal in retainer. Use new gasket and install seal retainer. See Figure 45. Tighten screws and nut to 15 N•m (133 lbf in). A. Seal Removal Notches
1. Crankshaft
2. Oil Seal
3. Seal
Retainer
4. Engine Block
5. Gasket
6. Stud
7. Screw
8. Nut
Figure 45. One-Piece Rear Seal Piston and Connecting Rod Assemblies Repair Connecting Rod Bearings, Replace NOTE: Connecting rod bearings are insert bearings that do not use shims for adjustment. These bearings are available in a standard size and the following undersizes: 0.025 mm (0.001 in.), 0.051 mm (0.002 in.), 0.254 mm (0.010 in.), and 0.508 mm (0.020 in.). If a bearing on a journal is worn, both the upper and lower half of the bearing must be replaced.
1. Remove oil sump and oil pump.
2. Mark caps for connecting rods so they can be installed in their correct locations and positions.
3. Push connecting rod away from crankshaft and remove upper bearing half. Wipe oil from bearing halves and bearing journal. Make sure all parts from each rod assembly remain together.
4. Use a micrometer to measure bearing journal. The bearing journal must be within the following specifications:
Out-of-round less than 0.0254 mm (0.001 in.)
Taper less than 0.0254 mm (0.001 in.)
If bearing journals are not within specifications, crankshaft must be removed and bearing journal ground to an undersize. If bearing journal cannot be repaired so bearing journal is a correct undersize, crankshaft must be replaced. See Engine Specifications, Crankshaft. 5. If bearing journal is within specifications, measure clearance between new bearing and crankshaft. Use Plastigage® or equivalent to check clearance:
a. Put a piece of Plastigage® across the full width of the bearing journal as shown in Figure 46. Do not rotate crankshaft when Plastigage® is between bearing and its journal. b. Install bearing cap and tighten bearing cap nuts first to 27 N•m (240 lbf in) and then an additional 70 degrees.
c. Remove bearing cap. The Plastigage® will be compressed and wider and will adhere to either the bearing or its journal. Use scale on envelope for Plastigage® to measure width of plastic at its widest point. The scale will indicate the clearance in millimeters or thousandths of an inch. See Figure 47. Figure 46. Plastigage® on Bearing Journal
Figure 47. Measuring Plastigage® on Bearing Journal
d. If clearance is greater than specifications, select a new undersize bearing set and install it. Measure clearance again. If clearance cannot meet specifications with available undersize bearings, bearing journal must be ground to a new undersize. If bearing journal is already at maximum undersize, crankshaft must be replaced.
e. If clearance is within specifications, lubricate bearing with engine oil and install bearing and bearing cap. First tighten nuts on bearing caps to 27 N•m (240 lbf in). After this step, tighten nuts an additional 70 degrees.
6. When all rod bearings have been replaced, use the following procedure to check side clearances between connecting rods and crankshaft:
a. Use a hammer to lightly hit connecting rod parallel to crankshaft journal to make sure there is clearance.
Figure 48. Measuring Connecting Rods Side Clearance
Piston and Connecting Rod Assemblies, Remove 1. Remove oil sump and oil pump.
3. If engine has been in service for many hours, a ridge can be worn in the top of the cylinder. This ridge can be removed with a ridge reamer tool. Turn crankshaft to lower piston to bottom of stroke in its cylinder. Put cloth on top of piston for a collector of metal particles. Use a ridge reamer to remove ridge at top of cylinder.
4. Clean carbon from top of each cylinder.
5. Put an identification mark on top of each piston.
6. Remove caps and bearings from each connecting rod. Keep caps and bearings with their original piston assemblies. Mark caps so they will be installed again in their original positions. Do not mix parts.
7. Push connecting rod and piston from cylinder. Temporarily install bearing cap on connecting rod to keep parts together.
CAUTION The pistons are aluminum alloy and can be damaged if they are hit with a hard object. The grooves for the piston rings are machined to close tolerances. Use a tool made to clean the grooves of the piston rings. Do not use a wire brush to clean a piston.
1. Remove piston rings from pistons.
2. Use a press to remove piston pins from piston. See Figure 49. Figure 49. Piston Pin Removal
Piston, Clean and Inspect WARNING Commercial cleaning solvents can be flammable and toxic and can cause severe skin irritation. When using commercial cleaning solvents, always comply with the solvent manufacturer’s recommended safety precautions.
Compressed air can move particles so they cause injury to the user or to other personnel. Make sure the path of the compressed air is away from all personnel. Wear protective goggles or a face shield to prevent injury to the eyes.
1. Use solvent to clean pistons and connecting rods. Use compressed air to dry parts.
2. Clean piston ring grooves with a ring groove cleaning tool.
3. Clean piston oil lubrication holes and slots.
4. Inspect pistons for wear, cracks, and damage. Replace a piston that is worn or damaged.
NOTE: If the cylinder bore must be repaired, the piston must be changed to the correct oversize. Check clearance of piston in its cylinder after surface of cylinder bore has been finished with a hone.
5. Check clearance of piston pin in piston. The normal clearance is shown in the Engine Specifications. The piston pin will normally fall from the hole in the piston by its own weight. The piston pin is a press fit in the connecting rod. The piston and piston pin are a matched set and must be replaced as a unit if the clearances are greater than the specifications. Cylinder Bores, Inspect and Repair Inspect cylinder bores for wear and damage. Measure cylinder bores in several positions as shown in Figure 50. Measure cylinder bore at right angles to centerline to find any distortion from wear. A cylinder that is out-of-round greater than 0.05 mm (0.002 in.) must be repaired. Figure 50. Cylinder Bore Measurement
Measure cylinder bore in positions from top to bottom to find any taper from wear. A normal wear pattern for a cylinder bore is shown in Figure 51. A cylinder that has a taper (measurement A that is 0.127 mm (0.005 in.) greater than measurement B) must have a new bore. A tool called a hone can be used to remove a small amount of taper from a cylinder bore. Use a boring machine to repair a badly worn cylinder. The boring machine will make a more accurate cylinder bore. The hone is then used to finish the surface of the cylinder bore. Figure 51. Pattern for Normal Cylinder Wear
A cylinder bore that has been repaired with a hone or a boring machine must be fitted with a piston that is the correct size. Measure outer diameter of piston and inner diameter of cylinder bore as shown in Figure 52. Using different oversize pistons in the engine does not affect the dynamic balance of the engine. Replacement pistons from standard size to 0.508 mm (0.020 in.) oversize normally have the same weight. The clearance specifications between a piston and its cylinder bore is shown in Engine Specifications. NOTE: Check clearance of piston rings in cylinder after surface of cylinder has been finished with a hone. New piston rings are available for the following piston sizes: standard size, and 0.127 mm (0.005 in.), 0.254 mm (0.010 in.), 0.508 mm (0.020 in.), and 0.762 mm (0.030 in.) oversize. The piston rings must match the size of the piston on which they are installed. Check side clearance and end clearance of piston rings as described in the following paragraphs.
Each compression ring has a mark on one surface. This mark must be toward the top of the cylinder when the piston ring is installed. The No. 1 compression ring normally has a chrome or molybdenum surface.
Figure 52. Piston and Cylinder Bore Gauge Points
The oil control ring has three pieces. There are two thin steel rings separated by a spacer.
1. Measure clearance between piston ring and groove in piston as shown in Figure 53. The clearances are shown in the Engine Specifications. Replace piston if clearances are greater than specifications. 2. Measure end clearance of each piston ring as shown in Figure 54. The end clearances are shown in the Engine Specifications. Install piston ring into cylinder where it will be used. Use a thickness gauge to measure the amount of end clearance. Replace piston if clearances are greater than the specifications. Figure 53. Piston Ring and Groove Clearance Check
Figure 54. Piston Rings End Clearance Check
NOTE: There are notches cast in the top of all pistons to indicate the correct assembly and installation. The pistons must always be installed with this notch toward the fan end of the engine. See Table 1. The connecting rods have a notch cast in the bearing journal as shown in Figure 55. This notch must be opposite the notch on the top of the piston when the piston and connecting rod are assembled. On later engines the flanges on the connecting rods and caps should face to the front of the engine on the left bank and to the rear of the engine on the right bank. 1. Notches on rod opposite notch in piston
Figure 55. Connecting Rod Identification
1. Assemble connecting rod to piston. Make sure the orientation of connecting rod and piston are correct as described in the NOTE above. Use a press to install piston pin into piston and connecting rod. Lubricate piston pin with engine oil during installation. 2. Check clearances of piston rings as described in Piston Rings. Install piston rings on piston as shown in Table 1. Table 1. Piston Rings Arrangement on Piston
A |
Position of Gap for Spacer of Oil Ring |
Fan End of Engine |
B |
Position of Gap for Oil Ring |
C |
Position of Gap for Second Compression Ring |
D |
Position of Gap for First Compression Ring |
Piston and Connecting Rod Assemblies, Install 1. Lubricate assembly with engine oil during installation. Arrange piston rings on piston as shown in Table 1. Install ring compressor on piston. 2. Make sure notch in piston is toward fan end of engine. Install piston and connecting rod assemblies in cylinder bores.
6. Install oil pump and oil sump. Flywheel and Flywheel Housing Repair 1. Replace ring gear (if applicable) on flywheel. During removal or installation, do not heat gear to more than 230°C (450°F).
2. During installation, push ring gear fully against flywheel.
3. The bearing in the flywheel can be replaced. Push old bearing from flywheel and push in new bearing.
GP/GLP/GDP070-110LG/MG, GC/GLC070-120LG/MG, GLC60-70CA (GC/GLC/GDC135-155CA) NOTE: For model GLP/GDP35-50LJ/MJ (GP/GLP/GDP070-120LJ/MJ), refer to the section Cooling System 700 YRM 740 for hydraulic pump drive.
When installing the flywheel on these units, refer to the section Hydraulic Pump Drive Assembly.
GDP60-70CA (GP/GLP/GDP135-155CA) Make sure dowel pin is installed in crankshaft. Install flywheel.
Units with a manual transmission: Make sure O-ring is installed between flywheel and crankshaft. Use a sealant (Yale Part No. 505970592) on heads of capscrews. Tighten capscrews for flywheel to 79 N•m (58 lbf ft).
Units with a powershift transmission: Tighten capscrews to 79 N•m (58 lbf ft).
Flywheel Housing, GP/GLP/GDP070-110LG/MG, GLP/GDP35-50LJ/MJ (GP/GLP/GDP070-120LJ/MJ), GC/GLC070-120LG/MG, GC080LJ-BCS, and GLC60-70CA (GC/GLC/GDC135-155CA) The flywheel housing on these units has the parts for the hydraulic pump drive assembly. When doing any service to the housing, refer to section Hydraulic Pump Drive Assembly.
Engine Adapter, GDP60-70CA (GP/GLP/GDP135-155CA) The engine adapter is used on engines with a manual transmission. When the seal in the adapter is replaced, use a sealant (Yale Part No. 505970592) between seal and adapter. When installing adapter on engine, make sure O-rings are installed under washers. Tighten capscrews for adapter to 48 N•m (35 lbf ft). See Figure 56.
1. Engine Adapter 2. Engine 3. Flywheel 4. Pilot Bearing |
5. Seal 6. Capscrew 7. Washer 8. O-Ring |
Figure 56. Engine Adapter GDP60-70CA (GP/GLP/GDP135-155CA) If any parts of the coolant pump are worn or damaged, replace coolant pump. Parts for the coolant pump are not available separately. During installation, apply a sealant to gasket for coolant pump. Tighten capscrews for coolant pump to 41 N•m (30 lbf ft). Adjust tension of belt as described in the Periodic Maintenance section for your lift truck. CAUTION DO NOT operate the engine without a thermostat. The engine and cooling system can be damaged.
When installing the thermostat, make sure flange is completely in its seat. Install gasket and housing. Tighten capscrews to 25 N•m (221 lbf in). Fan Mount Repair (Early Models) The fan mount has the shaft and bearings for the fan. On some early units the mount has an idler pulley for adjustment of the fan belt. When the fan is installed, tighten capscrews to 20 N•m (177 lbf in). See Figure 57.
1. Inner Snap Ring 2. Outer Snap Ring |
3. Bearing 4. Fan Mount 5. Shaft |
Figure 57. Fan Mount (Early Models) Fan Mount Assembly Repair (Late Models) NOTE: For model GLP/GDP35-50LJ/MJ (GP/GLP/GDP070-120LJ/MJ), refer to the section Cooling System 700 YRM 740. WARNING Do not try to disassemble the belt tensioner. There is a strong spring inside the tensioner that, if removed, can cause an injury.
The fan mount assembly includes brackets and mounts that hold fan, belt tensioner, alternator, and hydraulic pump (where used) to engine. When the fan is installed, tighten capscrews to 20 N•m (177 lbf in). See Figure 58. NOTE: GLC60-70CA (GC/GLC/GDC135-155CA) and GDP60-70CA (GP/GLP/GDP135-155CA) shown, others similar.
A. Early Models
B. Late Models
1. Mount
2. Bearing
3. Snap Ring
4. Shaft
5. Hub
6. Spacer
7. Fan Pulley
8. Fan
9. Drive Belt
10. Belt Tensioner
11. Crankshaft Pulley
12. Bracket
13. Alternator Bracket
14. Tensioner Bracket
Figure 58. Fan Mount Assembly NOTE: For model GLP/GDP35-50LJ/MJ (GP/GLP/GDP070-120LJ/MJ), refer to Cooling System 700 YRM 740. 1. Check alignment of fan, alternator, and crankshaft pulleys. The pulleys must be aligned correctly to prevent damage to drive belt. See Figure 59. NOTE: GC/GLC070-120LG/MG, GP/GLP/GDP070-110LG/MG shown, others similar.
1. Alternator Pulley 2. Fan Pulley 3. Water Pump Pulley |
4. Crankshaft Pulley 5. Drive Belt 6. Tensioner Pulley |
Figure 59. Drive Belt Arrangement
2. Install drive belt tensioner on bracket and tighten bolts. See Figure 60. Make sure lug on back of tensioner fits into lower hole in bracket for new drive belts. Do not use the upper hole when installing a NEW drive belt. Putting the lug in the upper hole is only necessary to extend the life of a used drive belt.
1. Bracket 2. Upper Hole 3. Pulley |
4. Tensioner 5. Alignment Lug 6. Lower Hole |
Figure 60. Drive Belt Tensioner Installation
CAUTION Do not use a pry bar to install the drive belt on the pulleys. The pry bar can damage the drive belt and pulleys.
3. Loosen top capscrew at alternator mount and move alternator toward engine. Install drive belt over fan and onto pulleys.
4. Use a socket with a long handle on capscrew for the pulley (Figure 60) on belt tensioner. (The capscrew has left-hand threads and will not loosen.) Use the handle to pull the pulley away from drive belt. While holding pulley away from belt, pull alternator away from engine (as far as it will move) and tighten capscrew at mount. Release pulley for belt tensioner. 5. After installation is complete, check position of indicator on tensioner. When tension is correct, indicator will be in the area (3) as shown in Figure 61. If indicator is in the area as shown by (4), change position of tensioner to upper hole (Figure 60). Use the procedure described in Step 4. If tension on drive belt is still not correct, install new drive belt. Also check that brackets and pulleys are installed correctly. 1. Tensioner
2. Indicator
3. Tension is Correct
4. Adjust Tension or Replace Drive Belt
Figure 61. Drive Belt Tension Check Valve Clearance Adjustment (Early Models) NOTE: The early models use rocker arm studs that are pressed into the head. 1. Disconnect negative cable at battery. Remove rocker covers.
2. Rotate engine until mark on vibration damper or crankshaft pulley is aligned with 0 timing mark on timing tab. Make sure valves for No. 1 cylinder are closed. If valves are moving as 0 timing mark is reached, engine is in firing position for No. 4 cylinder; rotate crankshaft one more turn to reach firing position for No. 1 cylinder. See Figure 62. 3. When engine is in No. 1 firing position, adjust valves for the following cylinders: Inlet Valves for Numbers: 1, 2, and 3 and Exhaust Valves for Numbers: 1, 5, and 6.
4. Adjust valve clearance by loosening nut for rocker arm until push rod is loose. Tighten nut for rocker arm until there is no clearance at push rod. Check clearance by rotating push rod while tightening nut. When there is no clearance at push rod, tighten nut for rocker arm one full turn. The additional turn of the nut will put the push rod in the seat of the valve lifter.
5. After the valves are adjusted in Step 3, rotate engine one full turn. Make sure timing marks are aligned. The valves on the No. 4 cylinder will be closed. When engine is in this position, adjust valves for the following cylinders: Inlet Valves for Numbers. 4, 5, and 6 and Exhaust Valves for Numbers. 2, 3, and 4.
6. Install valve covers. Connect battery cable. Start engine and check for correct operation.
NOTE: Early models shown.
Figure 62. Valve Clearance Adjustment Valve Clearance Adjustment (New Models) NOTE: The new models use rocker arm studs screwed into the head. The new models have a valve system that is not adjustable. After the valve system has been assembled, tighten nuts for rocker arms to 25 N•m (221 lbf in). The hydraulic valve lifter acts as an automatic adjuster and maintains zero lash in the valve train. Check the compression as follows: 1. Remove all spark plugs.
2. Make sure battery is fully charged.
3. Install a compression gauge. Hold throttle open and crank engine with starter. The minimum pressure is 690 kPa (100 psi). The lowest pressure in a cylinder must not be less than 70% of the highest pressure. 4. If the readings are lower than the minimum readings, there is a problem with the valves, piston rings, or cylinder head gasket. Do the following tests to find the problem:
a. Add approximately 30 ml (1 oz) of engine oil to each cylinder at spark plug hole.
b. Crank engine approximately ten revolutions to distribute oil.
c. Install compression gauge and do the same tests as described in Step 3. d. If compression pressure increases to a normal reading, the low pressure was caused by worn or damaged piston rings. The cylinder bore can also be damaged.
e. If compression pressure does not increase, the low pressure was caused by worn valves, valve seats, or valve guides.
f. If low pressure readings are in two cylinders next to each other, the cylinder head gasket can be leaking.
Number of cylinders |
6 |
Firing order |
1−6−5−4−3−2 |
Bore |
101.62 to 101.64 mm (4.0008 to 4.0016 in.) |
Stroke |
88.39 mm (3.480 in.) |
Compression Ratio |
9.2:1 |
Displacement |
4.3 liter (262.4 in.3) |
Governor speed |
See Periodic Maintenance section for each model of lift truck. |
Valve seat specifications |
|
Valve seat width (inlet valves) |
Early Models |
1.02 to 1.65 mm (0.040 to 0.065 in.) |
Late Models |
0.89 to 1.52 mm (0.035 to 0.060 in.) |
Valve seat width (exhaust valves) |
Early Models |
1.65 to 2.49 mm (0.065 to 0.098 in.) |
Late Models |
1.57 to 2.36 mm (0.062 to 0.093 in.) |
Clearance between inlet valve and guide |
Early Models |
0.02 to 0.09 mm (0.001 to 0.0035 in.) |
Late Models |
0.0254 mm (0.001 in.) max |
Clearance between exhaust valve and guide |
Early Models |
0.02 to 0.12 mm (0.001 to 0.0047 in.) |
Late Models |
0.0508 mm (0.002 in.) max |
Valve spring, free length |
|
Leak rate |
12 to 90 seconds with 50-lb load |
Body diameter |
21.3868 to 21.4046 mm (0.8420 to 0.8427 in.) |
Plunger travel |
3.175 mm (0.125 in.) |
Clearance in bore |
0.0635 mm (0.0025 in.) |
Lifter bore diameter |
21.425 to 21.450 mm (0.8435 to 0.8445 in.) |
Variation from front to rear of a cam lobe |
Taper with larger dimension away from No. 1 piston |
Bearing journals, diameter (All engines) |
47.45 to 47.48 mm (1.8681 to 1.8693 in.) |
Bearing journals, clearance |
0.01778 to 0.9685 mm (0.0007 to 0.0381 in.) |
Variation of a bearing journal in either diameter or axial direction |
0.03 mm (0.001 in.) |
Axial clearance |
0.10 to 0.30 mm (0.004 to 0.012 in.) |
Piston diameter (see gauge points in Figure 52) |
Cylinder Bore Out-of-round (see Figure 50) |
0.0508 mm (0.002 in.) |
Maximum cylinder taper |
0.025 mm (0.001 in.) |
Clearance at bottom of cylinder |
0.068 mm (0.0027 in.) |
Piston ring to groove clearance for piston rings (see Figure 53) |
Compression rings |
0.107 mm (0.0042 in.) |
Oil ring to groove clearance |
Early Models |
0.203 mm (0.008 in.) max |
Late Models |
0.508 to 2.032 mm (0.02 to 0.08 in.) |
Piston ring end clearance (see Figure 54) |
Compression rings |
Early Models |
0.89 mm (0.035 in.) |
Late Models |
1.524 to 0.88 mm (0.06 to 0.035 in.) |
Oil ring |
Early Models |
1.65 mm (0.065 in.) |
Late Models |
0.23 to 1.65 mm (0.009 to 0.065 in.) |
Piston pin to piston clearance |
0.025 mm (0.001 in.) |
Piston pin to connecting rod clearance |
0.020 to 0.040 mm (0.0008 to 0.0016 in.) |
Diameter of main bearing journal |
Number 1 |
62.20 to 62.22 mm (2.4488 to 2.4496 in.) |
Number 2, 3 |
62.20 to 62.21 mm (2.4488 to 2.4492 in.) |
Number 4 |
62.18 to 62.20 mm (2.4480 to 2.4488 in.) |
Out-of-round of main bearing journal (maximum) |
0.0254 mm (0.001 in.) |
Taper of main bearing journal (maximum) |
0.0254 mm (0.001 in.) |
Clearance between journals and main bearings |
Early Models |
Number 1 |
0.025 to 0.038 mm (0.0010 to 0.0015 in.) |
Number 2, 3 |
0.025 to 0.064 mm (0.0010 to 0.0025 in.) |
Number 4 |
0.064 to 0.090 mm (0.0025 to 0.0035 in.) |
Late Models |
Number 1 |
0.0254 to 0.05 mm (0.0010 to 0.0020 in.) |
Number 2, 3, 4 |
0.025 to 0.006 mm (0.0010 to 0.0002 in.) |
Available undersize main bearings |
−0.0254 mm (−0.001 in.) |
−0.0508 mm (−0.002 in.) |
−0.2285 mm (−0.009 in.) |
−0.25 mm (−0.010 in.) |
−0.50 mm (−0.020 in.) |
Axial Clearance (crankshaft to thrust surface main bearing) |
Early Models |
0.15 to 0.18 mm (0.006 to 0.007 in.) |
Late Models |
0.050 to 0.20 mm (0.002 to 0.008 in.) |
Diameter of connecting rod journals |
57.12 to 57.14 mm (2.2488 to 2.2496 in.) |
Out-of-round of bearing journal (maximum) |
0.0254 mm (0.001 in.) |
Taper of bearing journal (maximum) |
0.0254 mm (0.001 in.) |
Clearance between crankshaft journals and connecting rod bearings |
0.076 mm (0.0030 in.) |
Available undersize connecting rod bearings |
−0.0254 mm (−0.001 in.) |
−0.0508 mm (−0.002 in.) |
−0.254 mm (−0.010 in.) |
−0.508 mm (−0.020 in.) |
Side clearance of connecting rod to crankshaft |
Early Models |
0.15 to 0.36 mm (0.006 to 0.014 in.) |
Late Models |
0.15 to 0.44 mm (0.006 to 0.017 in.) |
Front bearing journal diameter |
54.99 to 55.00 mm (2.1650 to 2.1654 in.) |
Rear Bearing Journal Diameter |
38.08 to 38.10 mm (1.4992 to 1.500 in.) |
Rear Bearing Journal Clearance |
0.025 to 0.091 mm (0.001 to 0.0036 in.) |
Oil pressure @ 2500 rpm |
170 to 241 kPa (25 to 35 psi) |
Minimum oil pressure |
Early Model @ idle rpm |
48 kPa (7 psi) |
Late Model @ 1000 rpm |
41.4 kPa (6 psi) |
Oil pressure switch ON |
20 to 39 kPa (2.9 to 5.7 psi) |
61 N•m (45 lbf ft)
Balance Shaft Gear Capscrew
20 N•m (177 lbf in) Plus 35 Degrees
Balance Shaft Retainer Capscrews
14 N•m (124 lbf in)
Camshaft Retainer Screws
14 N•m (124 lbf in)
Camshaft Sprocket Capscrews
28 N•m (21 lbf ft)
Camshaft Sprocket Nut
28 N•m (21 lbf ft)
Chain Control Block for Hydraulic Pump Drive
19 N•m (168 lbf in) with Adhesive Sealant
Connecting Rod Cap See Text
Coolant Pump to Engine Block
41 N•m (30 lbf ft)
Cooling Fan to Pulley
24 N•m (212 lbf in)
Cylinder Head See text
Distributor Mount Capscrew
34 N•m (25 lbf ft)
Exhaust Manifold
15 N•m (133 lbf in) - first step
30 N•m (22 lbf ft) - second step
Flywheel
80 N•m (60 lbf ft)
Flywheel Housing
48 N•m (35 lbf ft)
Inlet Manifold to Cylinder Head (Early Models)
48 N•m (35 lbf ft)
Inlet Manifold to Cylinder Head (Late Models)
15 N•m (133 lbf in) - in three steps
Main Bearing Cap
106 N•m (78 lbf ft)
Motor Mount to Engine
GC/GLC070-120LG/MG, GP/GLP/GDP070-110LG/MG 31 N•m (23 lbf ft)
GLC60-70CA (GC/GLC/GDC135-155CA), GDP60-70CA (GP/GLP/GDP135-155CA) 50 N•m (37 lbf ft)
Oil Pump Cover
14 N•m (124 lbf in)
Oil Pump to Crankcase
90 N•m (66 lbf ft)
Oil Pressure Switch
27 N•m (20 lbf ft)
Oil Screen Support to Crankcase
50 N•m (37 lbf ft)
Oil Sump to Crankcase (Early Models)
(1/4-20) 10 N•m (89 lbf in)
(5/16-18) 19 N•m (168 lbf in)
Oil Sump to Crankcase (Late Models)
Capscrews 25 N•m (18 lbf ft)
Nuts 25 N•m (18 lbf ft)
Oil Sump Drain Plug
25 N•m (18 lbf ft)
Rear Oil Seal Retainer Screws and Nut
15 N•m (133 lbf in)
Rocker Arm Cover
10 N•m (89 lbf in)
Rocker Arm Nuts (Late Models)
25 N•m (18 lbf ft)
Rocker Arm Studs
47 N•m (35 lbf ft)
Rocker Arm Bolts (Model Year 2002 or Later Engines)
30 N•m (22 lbf ft)
Thermostat Housing
25 N•m (18 lbf ft)
Timing Cover
14 N•m (124 lbf in)
Valve Lifter Retainer Capscrews
16 N•m (142 lbf in)
Vibration Damper
PROBLEM POSSIBLE CAUSE PROCEDURE OR ACTION
When the key switch is in the START position, engine does not crank. |
Battery is not fully charged. |
Connections at the battery are loose or they have corrosion. |
Clean and tighten battery connections. |
Key switch does not operate correctly. |
Check operation of the key switch. Check electrical wiring. Install new key switch. |
Starter or starter circuit is damaged. |
Check starter, starter relay, and wiring. Install new parts as required. |
There is a seizure of parts in the engine or ring gear is damaged. |
Rotate crankshaft manually. If crankshaft will rotate, check ring gear, if not overhaul engine. |
The engine will not start. |
No fuel in fuel tank or fuel not entering engine. |
Fill tank with correct fuel. If LPG, open shutoff valve. Check fuel delivery system (fuel pump, lines, etc.). Install new parts as required. |
Cranking speed is too slow. Battery is not fully charged. |
Charge battery or install new battery. |
Valves are worn or damaged. |
Grind valves. Install new valves. |
Low compression. The piston rings are worn or damaged. |
Install new piston rings. Overhaul engine. |
Ignition system does not operate correctly. |
Check spark delivery system. Repair or install new parts as required. |
Ignition timing is not correct. |
Adjust timing. Check timing chain and sprockets. |
The engine does not run smoothly. |
Valves are not adjusted correctly. |
Cylinder head has cracks. |
Install new cylinder head. |
There is a leak in the intake system. |
Ignition timing is not correct. |
Spark plugs are worn or damaged. |
Ignition system does not operate correctly. |
See sections for Electrical Systems for more information. |
The engine does not have enough power. |
Restriction in air inlet. The air filter is dirty. |
Check air restriction indicator. Clean or install new filter element. |
Fuel is the wrong type or grade. |
Drain fuel. Fill with correct fuel. |
Ignition timing is not correct. |
Valve mechanism is damaged. |
Repair or install new parts. |
Piston assemblies are damaged. |
Repair or install new parts. Overhaul engine. |
Valve timing is not correct. |
Exhaust system has restrictions. |
Remove restrictions. Install new parts as necessary. |
There is noise inside the engine. |
Main bearings are worn or damaged. |
Install new main bearings or overhaul engine. |
Bearings for the connecting rods are worn or damaged. |
Install new rod bearings or overhaul engine. |
Pistons or rings are worn or damaged. |
Install new rings and piston or overhaul engine. |
Check thermostat. Check cooling system (radiator, fan, drive belt, etc.). Clean and repair as required. |
Low oil pressure. Not enough oil in the engine. |
Check oil level. Add oil to full mark on dipstick. Check oil pressure. Repair oil pump. Overhaul engine. |
Tighten flywheel mounting bolts. |
There is a leak in the exhaust system. |
Valve mechanism is damaged. |
Repair or install new parts as required. |
Valves are not adjusted correctly. |
Check and adjust valve clearance. |
The engine makes noise during acceleration. |
Clean spark plugs and reinstall. |
Spark plugs are the wrong type or heat range. |
Install new spark plugs of correct type and heat range. |
Ignition timing is not correct. |
Check and adjust ignition timing. |
Fuel is the wrong type or grade. |
Drain fuel. Fill with correct fuel. |
There is too much carbon in the combustion chamber (preignition). |
Put truck in hard work cycle. Add engine cleaner to fuel. Do top engine overhaul. |
Check thermostat. Check cooling system (radiator, fan, drive belt, etc.). Clean or repair as required. |
Fuel system is not adjusted correctly. |
The engine is too hot during operation. |
There is not enough coolant in the cooling system. |
Check coolant level in radiator and coolant recovery bottle. Add coolant to correct level. |
Drain and flush radiator. Clean radiator fins with high pressure air or water in reverse direction of normal airflow. Refill with clean coolant. |
Drive belt for water pump is not adjusted correctly, worn, or broken. |
Check water pump drive belt. Adjust or install new belt as required. |
Thermostat is wrong heat range or does not operate correctly. |
Check heat range. Install new thermostat. |
Cooling system has restrictions. |
Drain and back-flush engine and radiator. Refill with clean coolant. |
Water pump worn or damaged. |
Exhaust system has restrictions. |
Check the exhaust system. Remove restrictions. |
The bearings in the engine are damaged. |
There is not enough oil in the engine. |
Add oil to full mark on dipstick. |
Oil in the engine is dirty. |
Make sure dirt is not entering engine through air inlet system. Drain and fill with clean oil. Reduce time interval for oil and filter change. |
Oil in the engine is the wrong type. |
Drain and fill with correct oil. |
Oil pump is worn or damaged. |
Connecting rod(s) and bearings have damage. |
Check and repair crankshaft. Install new connecting rods and bearings. |
Camshaft and bearings have damage. |
Install new camshaft and bearings. |
Passages for oil have restrictions. |
Remove restrictions or overhaul engine. |
Bearings are not installed correctly. |
Install new bearings or overhaul engine. |
