Isuzu Cars and Trucks 1981-1991

Camshaft

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REMOVAL AND INSTALLATION
G180Z and G200Z Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the rocker arm cover.
  4.  
  5. Rotate the engine until the No. 4 cylinder is at TDC (top dead center) on the compression stroke. Remove the distributor cap and mark the rotor to housing position.
  6.  
  7. Release the tension on the automatic timing chain adjuster by performing the following procedures:
  8.  
    1. Using a small pry bar, depress the lock lever on the automatic adjuster rearward.
    2.  
    3. Push on the automatic adjuster shoe and lock it into the retracted position by releasing the lever.
    4.  

  9. Remove the camshaft sprocket-to-camshaft bolt, the sprocket and suspend the assembly on the wire; allow the chain to remain on the sprocket.
  10.  
  11. Remove the rocker arm brackets-to-cylinder head bolts and the rocker arm bracket assembly from the cylinder head.
  12.  
  13. Remove the camshaft from the cylinder head.
  14.  



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Fig. Camshaft timing marks G180Z and G200Z engines



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Fig. Tightening rocker arm retainers G180Z and G200Z engines

To install:

  1. Lubricate the camshaft with engine oil and install it onto the cylinder head.
  2.  
  3. Install the rocker arm assembly onto the cylinder head and torque the bolts to 16 ft. lbs. (21 Nm).
  4.  
  5. Align the camshaft sprocket hole with camshaft dowel pin and install the sprocket. Torque the camshaft sprocket-to-camshaft bolt to 50 and 1965 ft. lbs. (68 and 1988 Nm).
  6.  
  7. Set the automatic adjuster by turning the adjuster slide pin 90and#x00B0; counterclockwise with a small pry bar.
  8.  
  9. Adjust the valve lash.
  10.  
  11. Install the rocker arm cover and make sure the alignment marks are aligned.
  12.  
  13. To complete the installation, reverse the removal procedures. Start the engine and check and/or adjust the timing.
  14.  

4XC1-U, 4XC1-T and 4XE1 SOHC Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Align the crankshaft pulley notch with the 0 mark on the timing cover.
  4.  
  5. Remove the cylinder head cover.
  6.  
  7. Remove the timing cover.
  8.  
  9. Loosen the camshaft timing gear bolts (DO NOT rotate the engine).
  10.  
  11. Loosen the timing belt tensioner and remove the timing belt from the camshaft timing gear.
  12.  
  13. Remove the rocker arm shaft/rocker arm assembly.
  14.  
  15. Remove the distributor bolt and the distributor.
  16.  
  17. Remove the camshaft and the camshaft seal.
  18.  



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Fig. Camshaft and related components 4XC1-U, 4XC1-T and 4XE1 engines

To install:

  1. Drive a new camshaft seal onto the camshaft using seal installation tool No. J35268 or equivalent. Place the camshaft in the cylinder head with the dowel pin in the camshaft facing forward.
  2.  
  3. Install the distributor and hold down bolt.
  4.  
  5. Install the rocker arm shaft/rocker arm assembly.
  6.  
  7. Install the timing belt to the camshaft timing gear and adjust tensioner.
  8.  
  9. Tighten the camshaft timing gear bolts (DO NOT rotate the engine).
  10.  
  11. Install the timing cover.
  12.  
  13. Install the cylinder head cover.
  14.  
  15. Align the crankshaft pulley notch with the 0 mark on the timing cover.
  16.  
  17. Connect the negative battery cable, start the engine and check for leaks.
  18.  

4ZC1-T, 4ZD1 and 4ZE1 Engines
  1. Remove the cam cover.
  2.  
  3. Rotate the camshaft until the No. 4 cyl. is in the firing position. Remove the distributor cap and mark the rotor-to-housing position.
  4.  
  5. Remove the timing belt as previously outlined.
  6.  
  7. Apply a detention to the camshaft pulley by placing a T-bar or equivalent over the front plate fitting bolt and loosen the pulley fitting bolt. Remove the camshaft pulley, do not lose the camshaft boss or key.
  8.  
  9. Sequentially loosen and remove the outermost one and remove the rocker arm shaft with the bracket as an assembly.
  10.  
  11. Remove the camshaft.
  12.  

To install:

  1. Use a liberal amount of oil to coat the camshaft before installing it. Be sure that the mark on the camshaft is facing upward when it is being installed.
  2.  
  3. Use the timing belt removal and installation procedure previously outlined in this section to finish the installation.
  4.  
  5. Install the rocker arm shaft with the bracket as an assembly.
  6.  
  7. Install the camshaft pulley and bolt.
  8.  
  9. Install the distributor and cap to the marked position.
  10.  
  11. Install the cam cover.
  12.  
  13. Connect the battery cable, start the engine and check for leaks.
  14.  

4XE1 DOHC Engine
  1. Disconnect the negative battery cable. Remove the engine center (head) cover from the engine.
  2.  
  3. Rotate the engine until the engine is at TDC on the compression stroke of the No. 1 cylinder, make sure timing mark is on the scale.
  4.  
  5. Remove the power steering pump drive belt, for vehicles with air conditioners, remove the power steering pump and compressor drive belt. Loosen the 2 power steering pump adjust plates bolts.
  6.  
  7. Remove the alternator drive belt from the crank pulley side. Disconnect the clip securing the high pressure air conditioning line to the strut tower.
  8.  
  9. Remove the upper timing belt cover.
  10.  
  11. Using a suitable engine hoist, slightly raise and support the engine safely.
  12.  
  13. Remove the passenger side engine mount from the engine. Disconnect the torque rod at the firewall.
  14.  
  15. Remove the passenger side engine mounting bracket from the engine. Using special crank pulley tool J-37988 or equivalent, remove the crank pulley bolt.
  16.  
  17. Raise the passenger side of the engine, be sure that the front wheels remain on the ground while lifting the engine. Raise the engine too high, it will lift the front wheels off the ground and may cause damage to the drive shaft universal joint.
  18.  
  19. Remove the timing belt lower cover. Remove the cranking pulley and extract up through the engine compartment. Refit the crank pulley bolt. Align the crank pulley timing gear to top dead center.
  20.  
  21. Loosen the tension pulley bolt a 1 / 2 turn counterclockwise. If the pulley bolt is loosened more than 1 / 2 a turn, the pulley will swing too far out of adjustment and may be difficult to readjust.
  22.  
  23. Mark the direction of rotation of the timing mark with a piece of chalk and remove the timing belt. Using and open end wrench, hole the camshaft from turning and remove the camshaft pulley(s).
  24.  


NOTE
Inspect the timing belt for signs of cracking, abnormal wear and hardening. Never expose the belt to oil, sunlight or heat. Avoid excessive bending, twisting or stretching.

  1. Remove the camshaft bearing cap bolts and bearing caps. Be sure to take note of the positions of the bearing caps before removing them. Lift the camshafts out of the cylinder head.
  2.  



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Fig. Camshaft sealant locations 4XE1 DOHC engines

To install:

  1. Install the camshaft, bearing caps and bolts. Torque the bearing cap bolt to 96 inch lbs. (11 Nm). Be sure to install the camshaft bearing caps in their proper position.
  2.  
  3. Using and open end wrench, hold the camshaft from turning and install the camshaft pulley(s).
  4.  
  5. Tighten the tension pulley bolt.
  6.  
  7. Install the timing belt lower cover.
  8.  
  9. Lower the passenger side of the engine.
  10.  
  11. Install the passenger side engine mounting bracket to the engine. Install the crank pulley bolt.
  12.  
  13. Connect the torque rod at the firewall.
  14.  
  15. Install the upper timing belt cover.
  16.  
  17. Install the alternator drive belt to the crank pulley side. Connect the clip securing the high pressure air conditioning line to the strut tower.
  18.  
  19. Install the power steering pump and air compressor drive belt.
  20.  
  21. Connect the negative battery cable. Install the engine center (head) cover to the engine. Start the engine and check for leaks.
  22.  

4ZD1 and 4ZE1 Engines
  1. Disconnect the negative battery cable.
  2.  
  3. Rotate the crankshaft to position the No. 4 cylinder on the TDC of its compression stroke.
  4.  
  5. Remove the distributor cap and move it aside. Matchmark the rotor to the distributor housing and the distributor housing to the engine. Remove the distributor.
  6.  
  7. Remove the rocker arm cover, the timing belt cover and the timing belt.
  8.  
  9. Remove the rocker arm assembly-to-cylinder head bolts, the rocker arm assembly and the camshaft. If necessary, remove the camshaft sprocket-to-camshaft bolt and the sprocket.
  10.  

To install:

  1. Lubricate the camshaft with engine oil and position it onto the cylinder head.
  2.  
  3. Install the rocker arm assembly and torque the bolts to bolts to 6 ft. lbs. (8 Nm) and the nuts to 16 ft. lbs. (22 Nm).
  4.  
  5. Align the timing marks and install the timing belt.
  6.  
  7. Using a new gasket, install the rocker arm cover.
  8.  
  9. Install the timing belt cover.
  10.  
  11. Align the matchmarks and install the distributor to the cylinder head.
  12.  
  13. To complete the installation, reverse the removal procedures.
  14.  
  15. With the timing marks aligned, start the engine, then, check and/or adjust the engine timing.
  16.  

V6 Engine

NOTE
Use long bolts threaded into the camshaft to help remove the shaft without damaging the camshaft bearings. Remove the camshaft slowly while supporting the weight with the long bolt.

  1. Relieve the fuel pressure. Disconnect the negative battery cable.
  2.  
  3. Remove the timing cover and the camshaft sprocket.
  4.  
  5. Remove the upper fan shroud and the radiator.
  6.  
  7. Disconnect the fuel line(s), the accelerator linkage, the vacuum hoses and electrical connectors from the throttle body unit.
  8.  
  9. Remove the rocker arm covers.
  10.  
  11. Loosen the valves, rotate them 90and#x00B0; and remove the pushrods; be sure to keep them aligned so they may be installed in their original positions.
  12.  
  13. Remove the intake manifold.
  14.  
  15. Using a hydraulic lifter removal tool, pull the valve lifters from the engine.
  16.  
  17. Using 3 long bolts, thread them into the camshaft holes. Grasp the bolts and carefully, pull the camshaft from the front of the engine.
  18.  


NOTE
All the camshaft bearing journals are the same diameter; exercise care in removing the camshaft so the bearings do not become damaged.



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Fig. Removing the camshaft V6 engines

To install:

  1. Lubricate the camshaft with engine oil and install it into the engine.
  2.  
  3. Using a hydraulic lifter installation tool, install the hydraulic lifters into the engine.
  4.  
  5. Using new gaskets and sealant, install the intake manifold.
  6.  
  7. Install the pushrods and the rocker arms.
  8.  
  9. Install the camshaft sprocket, the timing chain and the front cover; be sure the timing marks are aligned.
  10.  
  11. Adjust the valves.
  12.  
  13. Using new gaskets, install the rocker arm covers.
  14.  
  15. To complete the installation, reverse the removal procedures. Refill the cooling system.
  16.  
  17. Start the engine and allow it to reach normal operating temperatures. Check and/or adjust the timing.
  18.  

4FB1 Diesel Engine
  1. Remove the cam cover.
  2.  
  3. Remove the timing belt.
  4.  
  5. Remove the rear plug and hold the shaft by attaching the fixing plate (J29761 or equivalent) into the slit at the rear of the camshaft.
  6.  
  7. Remove the camshaft pulley bolt, then remove the pulley with a gear puller.
  8.  
  9. Remove the rocker arms and shaft.
  10.  
  11. Remove the bolts attaching the front head plate and remove the plate.
  12.  
  13. Remove the bolts attaching the camshaft bearing caps. Remove the caps and bearings.
  14.  
  15. Remove the camshaft oil seal, then remove the camshaft.
  16.  



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Fig. Bolt loosening sequence for removing rocker arm assembly 4FC1 diesel engine

To install:

  1. Use a liberal amount of clean oil to coat the camshaft and journals during assembly. Install the camshaft and torque the rocker arm assembly to 18 ft. lbs. (25 Nm).
  2.  
  3. Install a new oil seal and apply Permatexand#x00AE; or equivalent gasket compound to the cylinder head fitting face of the No. 1 camshaft bearing cap.
  4.  
  5. Install the rocker arm cover and complete installation procedures.
  6.  

C223, C223-T Diesel Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Drain the crankcase. Remove the oil pan and the oil pump.
  4.  


CAUTION
The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

  1. Remove the timing belt cover, the timing belt, the camshaft sprocket.
  2.  
  3. Remove the rocker arm assembly, the pushrods and the valve lifters; be sure to keep the parts in order for reinstallation purposes.
  4.  
  5. Remove the camshaft retainer-to-engine bolts and the retainer. Using a small prybar, pry the oil seal from the cylinder block.
  6.  
  7. Screw a bolt into the camshaft and carefully remove the camshaft from the front of the engine; be careful not to damage the bearing surfaces.
  8.  
  9. Inspect the camshaft for wear, scoring and/or damage; if necessary, replace it.
  10.  



Click image to see an enlarged view

Fig. Camshaft removal C223 and C223-T diesel engines

To install:

  1. Lubricate the camshaft with engine oil and insert it into the front of the engine.
  2.  
  3. Using a new oil seal, lubricate the seal lips with engine oil and install it into the engine.
  4.  
  5. Install the camshaft retainer and the camshaft sprocket.
  6.  
  7. Install the oil pump and the oil pan.
  8.  
  9. Install the valve lifters, the pushrods and the rocker arm assembly.
  10.  
  11. Install and adjust the timing belt. Install the timing belt cover.
  12.  
  13. Rotate the crankshaft to bring the No. 1 piston to TDC of the compression stroke and adjust the valve lash.
  14.  
  15. To complete the installation, reverse the removal procedures.
  16.  
  17. Refill the cooling system and the crankcase.
  18.  
  19. Connect the negative battery cable. Start the engine, allow it to reach normal operating temperatures.
  20.  
  21. Check and/or adjust the idle speed and timing.
  22.  

CAMSHAFT BEARING REMOVAL AND INSTALLATION

NOTE
The V6 and C223 diesel engines are equipped with removable camshaft bearings. The remaining engines do not have removable camshaft bearings. The journal is cast into the head and acts as the bearing also. NOTE: It is recommended that the engine be removed from the vehicle before attempting this procedure.

The camshaft, lifters, flywheel and the expansion plug (at the rear of the camshaft) must be removed. Drive the expansion plug out from the inside of the engine block.



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Fig. Make sure the oil ports are aligned with the bearing ports in the block

ALL V6 AND C223 DIESEL ENGINES

To remove the camshaft bearings, the camshaft, lifters, flywheel, rear camshaft expansion plug, and crankshaft must be removed.

Camshaft bearings can be replaced with engine completely or partially disassembled. To replace bearings without complete disassembly remove the camshaft and crankshaft leaving cylinder heads attached and pistons in place. Before removing crankshaft, install rubber fuel hoses on the threads of connecting rod bolts to prevent damage to crankshaft. Fasten connecting rods against sides of engine so they will not be in the way while replacing camshaft bearings. Use rubber bands and the oil pan bolts to hold the connecting rods away from the crankshaft during removal.

If excessive wear is indicated, or if the engine is being completely rebuilt, camshaft bearings should be replaced as follows: Drive the camshaft rear plug from the block. Assemble the removal puller with its shoulder on the bearing to be removed. Gradually tighten the puller nut until bearing is removed. Remove remaining bearings, leaving the front and rear for last. To remove front and rear bearings, reverse position of the tool, so as to pull the bearings in toward the center of the block. Leave the tool in this position, pilot the new front and rear bearings on the installer, and pull them into position: Return the tool to its original position and pull remaining bearings into position.


NOTE
Ensure that oil holes align when installing bearings.

Replace camshaft rear plug, and stake it into position to aid retention.



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Fig. Removal and installation of the camshaft bearings V6 engines



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Fig. Aligning the camshaft bearing oil holes with a piece of wire bent at a 90and#x00B0; angle. The holes MUST be aligned

INSPECTION

Using solvent, degrease the camshaft and clean out all of the oil holes. Visually inspect the cam lobes and bearing journals for excessive wear. If a lobe is questionable, check all of the lobes as indicated. If a journal or lobe is worn, the camshaft MUST BE reground or replaced.


NOTE
If a journal is worn, there is a good chance that the bearings or journals are worn and need replacement.

If the lobes and journals appear intact, place the front and rear journals in V-blocks and rest a dial indicator on the center journal. Rotate the camshaft to check the straightness. If deviation exceeds 0.001in. (0.0254mm), replace the camshaft.

Check the camshaft lobes with a micrometer, by measuring the lobes from the nose to the base and again at 90and#x00B0; (see illustration). The lobe lift is determined by subtracting the second measurement from the first. If all of the exhaust and intake lobes are not identical, the camshaft must be reground or replace.



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Fig. Camshaft run-out check



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Fig. Measuring camshaft lift

 
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