GM Lumina/Silhouette/Transport APVs 1990-1999 Repair Guide

Timing Chain Cover and Seal

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The timing chain cover may also be called the engine front cover in some instances. This cover houses the timing chain and gear assemblies (camshaft gear and crankshaft gear). If the engine employs a balancer shaft, then the balance shaft gear is also housed in the front cover. It is also the front sealing surface for the oil pan. In some cases, it may even house the oil pump.

REMOVAL AND INSTALLATION



3.1L Engine
  1. Disconnect the negative battery cable.
  2.  
  3. Drain and recycle the engine coolant.
  4.  
  5. Remove the serpentine belt and tensioner.
  6.  
  7. Unbolt the power steering pump and position it aside.
  8.  
  9. Raise and safely support the vehicle.
  10.  
  11. Remove the right side tire and wheel assembly, then remove the inner splash shield.
  12.  
  13. Remove the crankshaft damper pulley.
  14.  
  15. Unbolt the starter, and move it aside.
  16.  
  17. Place a suitable jack under the transaxle-to-engine mount.
  18.  
  19. Remove the engine mount bolts and mount.
  20.  
  21. Raise the engine for access.
  22.  
  23. Disconnect the radiator hose from the water pump.
  24.  
  25. Remove the cover bolts.
  26.  
  27. Lower the oil pan as outlined previously in this section.
  28.  
  29. Disconnect the heater coolant hose from the cooling system fill pipe.
  30.  
  31. Remove the bypass and overflow hoses.
  32.  
  33. Remove the upper front cover bolts.
  34.  
  35. Remove the serpentine belt pulley.
  36.  
  37. Remove the engine front cover. Inspect the sealing surfaces on the front cover and block; clean the surfaces with degreaser.
  38.  

See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: Exploded view of the front cover, gasket and related components

To install:
  1. Position a new gasket, making sure not to damage sealing surfaces.
  2.  
  3. Apply a suitable sealant to the bottom-sealing surface of front cover
  4.  
  5. Place the front cover on the engine, then install the upper cover bolts.
  6.  
  7. Install the serpentine belt pulley.
  8.  
  9. Install the oil pan as described earlier in this section.
  10.  
  11. Install the remaining cover bolts.
  12.  
  13. Attach the engine mount to the engine.
  14.  
  15. Lower the engine into the frame, align the engine mount and install the nuts. Tighten to 35 ft. lbs. (48 Nm).
  16.  
  17. Install the crankshaft damper, using the special tool as required.
  18.  
  19. Install the flywheel cover on the transaxle.
  20.  
  21. Install the inner splash shield, install the tire and wheel assembly.
  22.  
  23. Carefully lower the vehicle.
  24.  
  25. Connect the radiator hose and heater hoses.
  26.  
  27. Install the power steering pump.
  28.  
  29. Install the serpentine belt tensioner and belt.
  30.  
  31. Fill the cooling system, change the oil.
  32.  
  33. Connect the negative battery cable.
  34.  

3.4L Engine

  1. Disconnect the negative battery cable.
  2.  
  3. Drain and recycle the engine coolant.
  4.  
  5. Drain the engine oil into a suitable container.
  6.  
  7. Remove the serpentine belt shield and belt.
  8.  
  9. Remove the crankshaft balancer, as described earlier in this section.
  10.  
  11. Remove the drive belt tensioner.
  12.  
  13. Remove the power steering pump with lines intact. Move the power steering pump aside.
  14.  
  15. Remove the thermostat bypass pipe from the engine front cover.
  16.  
  17. Disconnect the lower radiator hose from the water pump.
  18.  
  19. Remove the water pump pulley. For more information, refer to the water pump procedure in this section.
  20.  
  21. Remove the crankshaft position sensor from the engine front cover.
  22.  
  23. Remove the engine front cover bolts, then remove the front cover.
  24.  
  25. Remove the front cover gasket, clean and check the gasket mating surfaces.
  26.  
  27. Remove the water pump from the engine front cover.
  28.  

See Figure 2

Click image to see an enlarged view

Fig. Fig. 2: Exploded view of the engine front cover and related components-3.4L engine

To install:
  1. Install the water pump to the engine front cover.
  2.  
  3. Coat both sides of the lower tabs of the engine front cover gasket with a suitable sealant.
  4.  
  5. Install the engine front cover gasket, then install the engine front cover. Tighten the bolts to the following specifications:
    1. Tighten the five small bolts to 20 ft. lbs. (27Nm)
    2.  
    3. Tighten the three large bolts to 41 ft. lbs. (55Nm)
    4.  
    5. Tighten the two long bolts to 35 ft. lbs. (47Nm)
    6.  

  6.  
  7. Install the crankshaft position sensor to the engine front cover.
  8.  
  9. Install the water pump pulley.
  10.  
  11. Install the drive belt shield.
  12.  
  13. Connect the hoses that were removed.
  14.  
  15. Move the power steering pump into position, then tighten the bolts securely.
  16.  
  17. Install the crankshaft balancer.
  18.  
  19. Install the drive belt tensioner and the drive belt.
  20.  
  21. Install the crankshaft balancer.
  22.  
  23. Fill the fluids (oil and coolant) to the proper levels.
  24.  
  25. Connect the negative battery cable.
  26.  

3.8L Engine

The following special tools are required for this operation: Flywheel holding tool, crankshaft balancer puller and torque angle meter.

  1. Remove the serpentine belt.
  2.  
  3. Raise and safely support the vehicle securely.
  4.  
  5. Remove the right front tire and wheel.
  6.  
  7. Remove the right inner fender splash shield.
  8.  
  9. Hold flywheel with the special tool to prevent it from turning, then remove the balancer bolt.
  10.  
  11. Remove the crankshaft balancer with a suitable puller, using 1 / 4 inch bolts to attach to the pulley. Screw in 1 / 4 inch. Turn the puller screw and remove the balancer.
  12.  

The balancer is serviced as an assembly. Do not attempt or separate the pulley from the balancer hub.

  1. Remove the crankshaft sensor shield and crankshaft sensor.
  2.  
  3. Remove the oil pan-to-front cover bolts.
  4.  
  5. Remove the coolant cover bolts.
  6.  
  7. Unfasten the front cover attaching bolts, then remove the cover.
  8.  

See Figure 3

Click image to see an enlarged view

Fig. Fig. 3: Exploded view of the front cover assembly-3.8L engine

To install:

If oil pan gasket is excessively swollen, the oil pan should be removed and the gasket replaced

  1. Install the gasket at the cylinder block
  2.  
  3. Apply a suitable sealant to the attaching bolt threads. Install the front cover and attaching bolts. Tighten bolts to 22 ft. lbs. (30 Nm).
  4.  
  5. Install the water pump pulley.
  6.  
  7. Install the oil pan-to-front cover bolts, and tighten to 10 ft. lbs. (14 Nm).
  8.  
  9. Install the crankshaft sensor, and the sensor shield.
  10.  
  11. Install the balancer and bolt. Tighten to 110 ft. lbs. (150 Nm), plus an additional 76° rotation using the torque angle meter.
  12.  
  13. Install the drive belt.
  14.  
  15. Reverse the removal process to complete the repair procedure.
  16.  

SEAL REPLACEMENT



To remove and replace the oil seal on this vehicle, you will need a suitable front cover aligner and seal installation tool. It will not require the removal of the front cover from the engine. To remove the cover seal without removing the front cover, use the following procedure.

  1. Removal the crankshaft damper as outlined earlier in this section.
  2.  
  3. Pry out the seal with a suitable tool, being careful not to scratch or mar any of the sealing surfaces.
  4.  

To install:
  1. Lubricate the seal with clean engine oil.
  2.  

See Figure 4

Click image to see an enlarged view

Fig. Fig. 4: Installing the front cover oil seal-3.8L engine shown

  1. Insert the seal in the front cover with the lip facing the engine.
  2.  
  3. Install the special tool and drive the seal into place.
  4.  
  5. Install the crankshaft damper. Check for fluid leaks.
  6.  

 
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