GM Caprice 1990-1993 Repair Guide

Camshaft

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REMOVAL AND INSTALLATION



See Figure 1



Click image to see an enlarged view

Fig. Fig. 1: Install 3 long bolts in camshaft to aid in removal and installation of camshaft

EXCEPT 5.0L (VIN Y) ENGINE
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the intake manifold
  4.  
  5. Remove the rocker arm assemblies and pushrods.
  6.  
  7. Loosen the belt tensioner and remove the serpentine belt.
  8.  
  9. Remove the upper fan shroud, radiator hoses, oil cooler lines and the radiator.
  10.  
  11. Remove the timing chain.
  12.  
  13. Properly discharge the air conditioning, disconnect and remove the condenser.
  14.  
  15. Remove the valve lifters.
  16.  
  17. Remove the camshaft retainer bolts and the camshaft retainer.
  18.  
  19. Install three 4 inch long bolts in the camshaft bolt holes and carefully pull camshaft from bearings.
  20.  

To install:
  1. Coat camshaft lobes and journals with prelube 1052365 or equivalent.
  2.  
  3. Carefully slide camshaft into the block.
  4.  
  5. Install the camshaft retainer and retainer bolts. Tighten bolts to 106 inch lbs. (12 Nm).
  6.  
  7. Install the timing chain.
  8.  
  9. Install new valve lifters to assure durability of the camshaft lobes and lifter rollers.
  10.  
  11. Install the air conditioning condenser.
  12.  
  13. Install the radiator, oil cooler lines and radiator hoses.
  14.  
  15. Install the serpentine drive belt.
  16.  
  17. Install the upper fan shroud.
  18.  
  19. Install the pushrods and rocker arm assemblies
  20.  
  21. Install the intake manifold.
  22.  
  23. Connect the negative battery, change the oil and filter, add coolant, and adjust valves.
  24.  

5.0L (VIN Y) ENGINE
  1. Properly discharge the air conditioning system. Disconnect the negative battery cable.
  2.  
  3. Drain the cooling system into a suitable container.
  4.  
  5. Remove the upper radiator baffle.
  6.  
  7. Disconnect the upper radiator hose.
  8.  
  9. Remove the radiator assembly.
  10.  
  11. Remove the air cleaner assembly.
  12.  
  13. Disconnect the throttle cable.
  14.  
  15. Remove accessory brackets and drive belts. Position accessories aside with lines and connectors attached.
  16.  
  17. Remove AIR pump pulley.
  18.  
  19. Remove the fan, fan clutch and water pump pulley.
  20.  
  21. Disconnect the thermostat bypass.
  22.  
  23. Disconnect the electrical and vacuum connections.
  24.  
  25. Remove the AIR pump.
  26.  
  27. Remove distributor with cap and wiring intact.
  28.  
  29. Remove crankshaft pulley and hub.
  30.  
  31. Remove the fuel pump.
  32.  
  33. Remove engine front cover.
  34.  
  35. Remove both valve covers.
  36.  
  37. Remove intake manifold, gaskets and seals.
  38.  
  39. Remove rocker arms assemblies, pushrods and valve lifters.
  40.  

All parts for each assembly must be kept together and reinstalled in the same location.

  1. Disconnect and plug the air conditioner condenser lines.
  2.  
  3. Remove the condenser assembly.
  4.  
  5. Remove bolt securing fuel pump eccentric, remove eccentric, camshaft gear, oil slinger and timing chain.
  6.  
  7. Remove camshaft retaining plate and flange adapter.
  8.  
  9. Remove camshaft by carefully sliding it out the front of the engine.
  10.  

To install:
  1. Lubricate the camshaft with 1051396 or equivalent, and carefully insert into journals.
  2.  
  3. Install camshaft flange adapter and retaining plate.
  4.  
  5. Timing chain and sprockets.
  6.  
  7. Install fuel pump eccentric.
  8.  
  9. Install camshaft thrust spring and button.
  10.  
  11. Install the front cover and fuel pump with new gaskets.
  12.  
  13. Install condenser assembly and lines.
  14.  
  15. Install valve lifters, pushrods and rocker arm assemblies.
  16.  
  17. Install valve covers.
  18.  
  19. Install intake manifold, with new gaskets. Connect fuel lines.
  20.  
  21. Install crankshaft pulley and hub.
  22.  
  23. Install AIR pump.
  24.  
  25. Connect all electrical connections and vacuum hoses.
  26.  
  27. Connect thermostat bypass hose.
  28.  
  29. Install water pump pulley, fan clutch and fan.
  30.  
  31. Connect AIR pump pulley.
  32.  
  33. Install remaining accessory brackets and drive belts.
  34.  
  35. Connect the throttle cable.
  36.  
  37. Install the air cleaner assembly.
  38.  
  39. Install the radiator, hoses and baffle.
  40.  
  41. Connect the negative battery cable and add engine coolant.
  42.  
  43. Check for leaks and recharge air conditioning.
  44.  

Camshaft Bearing Removal and Installation

See Figure 2



Click image to see an enlarged view

Fig. Fig. 2: Checking camshaft bearing oil hole alignment - 5.0L (VIN Y) engine

It is recommended that the engine be removed from the vehicle before attempting this procedure.

ALL 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, tape 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.

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. Assembly 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 as follows:



Except 5.0L (VIN Y) engine: Ensure the No. 1 (front) camshaft bearing holes are an equal distance from the 6 o'clock position on 1990-91 engines or positioned at the 1 o'clock and 5 o'clock positions on 1992-93 engines. The No. 2 thru 4 (3 on V6 engine) inner bearing holes must be positioned at the 5 o'clock position towards the left side (drivers) of the engine, even with the bottom of the cylinder bore. The No. 5 (4 on V6 engine) rear bearing oil holes must be positioned at 12 o'clock.
 
5.0L (VIN Y) engine: Ensure the bearing oil holes and engine block oil passages are aligned. Use a piece of 3/32 in. brass rod as illustrated to check for proper alignment.
 

Return the tool to its original position and pull remaining bearings into position.

Ensure that oil holes are properly aligned. Replace camshaft rear plug, and stake it into position to aid retention.

CAMSHAFT INSPECTION



The lobe lift may be checked without removing the camshaft, simply remove the valve cover and rotate the engine while observing each rocker assembly. There should be a substantial and consistent amount of lift between all rockers. If a camshaft lobe is excessively worn there is usually some rocker arm play and valve noise during engine operation.

The 5.0L (VIN Y) is prone to excessive rocker arm and bridge wear, these parts should be thoroughly cleaned and inspected.

If the camshaft is suspected of excessive wear, removal will be necessary for a more thorough examination. Once removed, the camshaft lobes should be examined for wear or pitting. The camshaft journals and bearings should also be inspected for wear and pitting. The journals can be measured using a micrometer and then compared to factory specifications.

 
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