GM Astro/Safari 1985-1996 Repair Guide

Camshaft Bearings

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REMOVAL & INSTALLATION



2.5L Engine

See Figure 1



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Fig. Fig. 1: Camshaft bearing replacement requires special bearing removal and installation tools-2.5L engine

The following procedure requires the use of the GM Camshaft Bushing Removal/Installation Adapter tool No. J-21437-1 or equivalent, and GM Camshaft Bushing Removal/Installation Handle tool No. J-21054-1 or equivalent.

  1. Refer to the Engine, Removal and Installation procedures in this section and remove the engine from the vehicle and secure it onto a work stand.
  2.  
  3. Refer to the Camshaft, Removal and Installation and the Oil Pan, Removal and Installation procedures in this section, then remove the camshaft and the oil pan from the engine.
  4.  
  5. Remove the flywheel-to-crankshaft bolts and the flywheel from the engine.
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  7. Using a blunt tool, drive the camshaft expansion plug from the rear of the engine.
  8.  
  9. Using the GM Camshaft Bushing Removal/Installation Adapter tool No. J-21437-1 or equivalent and a hammer, drive the front camshaft bearing toward the rear and the rear camshaft bearing toward the front of the engine.
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  11. Install the GM Camshaft Bushing Removal/Installation Handle tool No. J-21054-1 or equivalent, onto the GM Camshaft Bushing Removal/Installation Adapter tool No. J-21437-1 or equivalent, and drive the center camshaft bearing toward the rear of the engine.
  12.  

To install:
  1. Position the bearing on the tool(s) and tighten the end bolt to draw the bearing into its seat. Make sure that the oil holes are lined up and free from obstructions.
  2.  

The front bearing MUST BE driven to approximately1/8in. (3mm) behind the front of the cylinder block; BE SURE that the oil hole-to-timing gear oil nozzle is uncovered.

  1. Install the camshaft being careful not to damage the new bearings.
  2.  
  3. Install the oil pan.
  4.  
  5. Install the engine.
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  7. Adjust the valves as outlined in the "Valve Lash'' procedures in Engine Performance & Tune-up .
  8.  
  9. Refill the cooling system and the crankcase. Start the engine, allow it to reach normal operating temperatures and check for leaks.
  10.  

4.3L Engine

See Figures 2 and 3



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Fig. Fig. 2: Special camshaft bearing removal and installation tools are necessary to replace the camshaft bearings



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Fig. Fig. 3: It is CRITICAL that the camshaft bearing oil holes are properly aligned. This wire tool has a 90° bend to help check for proper oil hole alignment

To perform this procedure, it is recommended to remove the engine from the vehicle.

The following procedure requires the use of the GM Camshaft Bearing Remover/Installer tool No. J-6098 (1985-95 models), J-33049 (1996 models) or equivalent.

  1. Refer to the Camshaft, Removal and Installation and the Crankshaft, Removal and Installation procedures in this section and remove the camshaft and the crankshaft from the engine; leave the cylinder heads attached and the pistons in place.
  2.  

Before removing the crankshaft, tape the threads of the connecting rod bolts or cover them with lengths of rubber hose in order to prevent damage to the crankshaft. Fasten the connecting rods against the sides of the engine, so that they will not be in the way while replacing the camshaft bearings.

  1. Drive the camshaft rear plug from the block.
  2.  
  3. Assemble the camshaft bearing remover/installer tool using its shoulder, on the bearing to be removed.
  4.  
  5. Gradually, tighten the puller nut until the bearing is removed. Remove the remaining bearings, leaving the front and the rear for last.
  6.  
  7. To remove the front and rear bearing, reverse the position of the tool, so as to press the bearings toward the center of the block.
  8.  

To install:
  1. Install the new bearings, leave the tool in this position, pilot the new front and rear bearings on the installer, then press them into position.
  2.  
  3. Return the tool to its original position and press the remaining bearings into position.
  4.  

Ensure that the oil holes align when installing the bearings.

  1. Coat a new camshaft rear plug using a suitable sealer, then drive it into position and stake it to aid in retention.
  2.  
  3. Install the camshaft using care not to damage the cam bearings.
  4.  
  5. Assemble the engine and install it into the vehicle as outlined in this section.
  6.  
  7. Refill all engine fluids, start the engine and check for proper operation.
  8.  

 
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