GM Bonneville/Eighty Eight/LeSabre 1986-1999

Camshaft, Bearings and Lifters

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REMOVAL & INSTALLATION



For the removal of the camshaft, the engine assembly will probably need to be removed from the vehicle.

3.8L (VIN 3) Engine
  1. Properly relieve the fuel system pressure.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the engine as outlined earlier in this section, and support it on a suitable engine stand.
  6.  
  7. Remove the intake manifold.
  8.  
  9. Remove the rocker arm covers.
  10.  
  11. Remove the rocker arm assemblies, pushrods and lifters, keeping the components in order for assembly.
  12.  
  13. Unfasten the retainers, then remove the timing chain cover.
  14.  

Align the timing marks of the camshaft and crankshaft sprockets to avoid burring the camshaft journals by the crankshaft.

  1. Remove the timing chain, camshaft sensor magnet assembly and sprockets.
  2.  
  3. Carefully remove the camshaft from the engine.
  4.  

To install:
  1. Coat the camshaft with lubricant 1052365 or equivalent, and install the camshaft.
  2.  
  3. Install the timing chain, camshaft sensor magnet assembly and sprockets.
  4.  
  5. Install the camshaft thrust button and front cover.
  6.  
  7. Complete installation by reversing the removal procedure.
  8.  
  9. Connect battery negative cable.
  10.  

3.8L (Except VIN 3) Engine

1988-90 VEHICLES
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the engine assembly and position in a suitable holding fixture.
  4.  
  5. Remove the intake manifold, the front timing cover, timing chain and sprockets.
  6.  
  7. Remove the valve covers, the rocker arm shaft or rocker arm assemblies, the pushrods and the hydraulic lifters.
  8.  

Keep all valve components in order so they may be reinstalled in their original positions.

  1. Carefully, slide the camshaft forward, out of the bearing bores; do not damage the bearing surfaces.
  2.  

To install:
  1. Clean the gasket mounting surfaces. Inspect the parts for wear and/or damage, replace if necessary.
  2.  
  3. Lubricate the valve lifters and camshaft with multi-lube 1052365 or equivalent, and install in the original positions.
  4.  

If equipped with 3.8L (VIN C or L) engine, align the camshaft gear with the balancer shaft gear timing marks.

  1. Carefully, install the camshaft in the engine.
  2.  
  3. Install the hydraulic lifters, pushrods, rocker arm assemblies and valve covers.
  4.  
  5. Install the timing chain and sprockets, front timing cover and intake manifold.
  6.  
  7. Install the engine assembly in the vehicle.
  8.  
  9. Connect the negative battery cable.
  10.  
  11. Fill cooling system and check for leaks. Start the engine and allow to come to normal operating temperature. Recheck for leaks. Top-up coolant.
  12.  

1991-99 VEHICLES

See Figure 1

  1. Disconnect the negative battery cable. Remove the engine assembly and position in a suitable holding fixture.
  2.  

Keep all valve components in order so they may be reinstalled in their original positions.

  1. Remove the intake manifold, the valve covers, rocker arms, pushrods and valve lifters.
  2.  
  3. Remove the crankshaft pulley/balancer, crankshaft sensor cover, sensor, front timing cover, timing chain and sprockets.
  4.  
  5. Unfasten the camshaft thrust plate retainers, then remove the thrust plate.
  6.  
  7. Carefully rotate and pull the camshaft out of the camshaft bearings.
  8.  



Click image to see an enlarged view

Fig. Fig. 1: Exploded view of the camshaft and related components - 1991-99 vehicles

To install:
  1. Clean the gasket mounting surfaces. Inspect the parts for wear and/or damage, replace if necessary.
  2.  
  3. Lubricate the valve lifters and camshaft with multi-lube 1052365 or equivalent, and install in the original positions.
  4.  

If equipped with 3.8L (VIN C or L) engine, align the camshaft gear with the balancer shaft gear timing marks.

  1. Carefully, install the camshaft in the engine and install the camshaft thrust plate.
  2.  
  3. Install the timing chain, sprockets and front timing cover.
  4.  
  5. Install the crankshaft sensor cover and crankshaft pulley/balancer.
  6.  
  7. Coat the valve lifters with a suitable prelube, then install them.
  8.  
  9. Install the pushrods, and rocker arms.
  10.  
  11. Install the valve covers and install the intake manifold.
  12.  
  13. Install the engine in the vehicle and connect the negative battery cable.
  14.  

INSPECTION



  1. Check the camshaft sprocket, keyway and threads, bearing journals and lobes for wear, galling, gouges or overheating. If any of these conditions exist, replace the camshaft.
  2.  

Do NOT attempt to repair the camshaft. Always replace the camshaft and lifters as an assembly. Old valve lifters will destroy a new camshaft in less time than it took you to replace the camshaft.

  1. Camshaft Lift Measurement:
    1. Lubricate the camshaft bearings with Assembly Lube 1051396 or equivalent.
    2.  
    3. Carefully install the camshaft into the block. If the cam bearings are damaged badly, set the camshaft on "V" blocks instead.
    4.  
    5. Install a dial indicator J-8520 and measure the camshaft lift.
    6.  
    7. Measure the bearing journals with a micrometer. Take measurements for run-out and diameter. If not within specification in the charts in the beginning of this section, replace the camshaft.
    8.  

  2.  

 
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