GM Camaro 1982-1992 Repair Guide

Camshaft and Bearings

Print

REMOVAL & INSTALLATION



See Figures 1 through 9


CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by the ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.



Click image to see an enlarged view

Fig. Fig. 1: Using bolts to aid in camshaft removal and installation



Click image to see an enlarged view

Fig. Fig. 2: Checking thrust plate clearance



Click image to see an enlarged view

Fig. Fig. 3: Camshaft bearing removal and installation



Click image to see an enlarged view

Fig. Fig. 4: Checking camshaft bearing oil hole alignment



Click image to see an enlarged view

Fig. Fig. 5: Checking camshaft straightness



Click image to see an enlarged view

Fig. Fig. 6: Camshaft lobe measurement



Click image to see an enlarged view

Fig. Fig. 7: Oil pump drive found on 2.5L engine



Click image to see an enlarged view

Fig. Fig. 8: A common oil pump drive found on V6 engines



Click image to see an enlarged view

Fig. Fig. 9: A common oil pump drive location on V8 engines

4-Cylinder Engines

There are two ways to go about this task: either remove the engine from the car, or remove the radiator, grill and any other supports which are directly in front of the engine. If the second alternative is chosen, you may have to disconnect the motor mounts, and raise the front of the engine. This will give you the necessary clearance to remove the camshaft from the engine.

  1. Drain the engine oil and the cooling system. Remove the radiator.
  2.  
  3. Remove the fan, drive belts and water pump pulley. Remove the valve cover. Loosen the rocker arms and pivot them, then remove the pushrods.
  4.  
  5. Remove the oil pump driveshaft and gear assembly. This is located under a small plate secured by two bolts near the oil filter. Remove the spark plugs.
  6.  
  7. Mark the position of the distributor rotor, housing, and engine block. Remove the distributor.
  8.  
  9. Remove the valve lifters. They are located behind the pushrod cover.
  10.  
  11. Remove the timing gear cover.
  12.  
  13. Insert a screwdriver through the holes in the timing gear and remove the 2 camshaft thrust plate screws.
  14.  
  15. Pull the camshaft and gear assembly out through the front of the engine block.
  16.  

When removing the camshaft, be careful not to damage the camshaft bearings.

  1. If the camshaft is to be removed from the timing gear, place the assembly in an arbor press and separate.
  2.  


CAUTION
When removing the timing gear from the camshaft, the thrust plate must be positioned so that the woodruff key does not damage it.

To install:
  1. To install the timing gear to the camshaft, press the assembly together and measure the end clearance. There should be 0.0015-0.0050 in. (0.038-0.127mm) between the thrust plate and the camshaft.
  2.  

If the clearance is less than 0.0015 in. (0.038mm), replace the spacer ring; if more than 0.0050 in. (0.127mm), replace the thrust ring.

  1. Lubricate the camshaft, bearings, and lifters. Slide the camshaft assembly into the engine and align the timing marks of the camshaft gear and crankshaft gear.
  2.  
  3. Complete the installation by reversing the removal procedure.
  4.  

V6 and V8 Engines
  1. Remove the engine from the vehicle or remove all components from the front of the engine (radiator, grille, etc.).
  2.  
  3. Remove the timing gear cover and chain.
  4.  
  5. Mark the distributor rotor, housing and engine block, then remove the distributor. Remove the fuel pump and fuel pump pushrod on carbureted engines.
  6.  
  7. Remove the intake manifold and valve covers. Loosen the rocker arms and pivot out of way. Remove the pushrods and valve lifters.
  8.  
  9. Remove the oil pump drive.
  10.  
  11. Slide the camshaft toward the front of the engine (be careful not to damage the camshaft bearings).
  12.  

To install:
  1. Lubricate all parts. Slide the camshaft onto the camshaft bearings.
  2.  
  3. Install the fuel pump and fuel pump pushrod.
  4.  
  5. Install the distributor and align all matchmarks.
  6.  
  7. Install the oil pump drive.
  8.  
  9. Install the valve lifters, pushrods and rocker arms.
  10.  
  11. Install the intake manifold and valve covers.
  12.  
  13. Install the timing and timing chain cover.
  14.  
  15. Install the radiator.
  16.  
  17. Fill the cooling system, start the engine and check for leaks.
  18.  

BEARING REMOVAL & INSTALLATION



It is recommended for a machine shop to perform these procedures.

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. 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 as follows:



4 cylinder engines: Ensure oil holes are properly aligned.
 
V6 engines: Ensure the rear and intermediate bearing oil holes are aligned between the 2 and 3 o'clock positions and the front bearing oil holes are at 1:00 and between 2 and 3 o'clock positions.
 
V8 engines: Ensure the No. 1 (front) camshaft bearing holes are an equal distance from the 6 o'clock position. The No. 2 through 4 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 bearing oil holes must be positioned at 12 o'clock.
 

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.

INSPECTION



Camshaft Lobe Lift

Check the lift of each lobe in consecutive order and make a note of the reading.

  1. Remove the fresh air inlet tube and the air cleaner. Remove the heater hose and crankcase ventilation hoses. Remove valve rocker arm cover(s).
  2.  
  3. Remove the rocker arm stud nut or fulcrum bolts, fulcrum seat and rocker arm.
  4.  
  5. Make sure the pushrod is in the valve tappet socket. Install a dial indicator so that the actuating point of the indicator is in the pushrod socket (or the indicator ball socket adapter tool is on the end of the pushrod) and in the same plane as the pushrod movement.
  6.  
  7. Disable the ignition and fuel systems.
  8.  
  9. Install a remote starter switch. Crank the engine with the ignition and fuel system disabled. Turn the crankshaft over until the tappet is on the base circle of the camshaft lobe. At this position, the pushrod will be in its lowest position.
  10.  
  11. Zero the dial indicator. Continue to rotate the crankshaft slowly until the pushrod is in the fully raised position.
  12.  
  13. Compare the total lift recorded on the dial indicator with the specification shown on the Camshaft Specification chart.
  14.  

To check the accuracy of the original indicator reading, continue to rotate the crankshaft until the indicator reads zero. If the lift on any lobe is below specified wear limits listed, the camshaft and the valve tappet operating on the worn lobe(s) must be replaced.

  1. Install the rocker arm, fulcrum seat and stud nut or fulcrum bolts. Adjust the valves, if required (refer to the valves procedure in this section).
  2.  
  3. Install the valve rocker arm cover(s) and the air cleaner.
  4.  

Camshaft End Play

On all gasoline V8 engines, prying against the aluminum-nylon camshaft sprocket, with the valve train load on the camshaft, can break or damage the sprocket. Therefore, the rocker arm adjusting nuts must be backed off, or the rocker arm and shaft assembly must be loosened sufficiently to free the camshaft. After checking the camshaft end play, check the valve clearance. Adjust if required (refer to procedure in this section).

  1. Push the camshaft toward the rear of the engine. Install a dial indicator or equivalent so that the indicator point is on the camshaft sprocket attaching screw.
  2.  
  3. Zero the dial indicator. Position a prybar between the camshaft gear and the block. Pull the camshaft forward and release it. Compare the dial indicator reading with the specifications.
  4.  
  5. If the end play is excessive, check the spacer for correct installation before it is removed. If the spacer is correctly installed, replace the thrust plate.
  6.  
  7. Remove the dial indicator.
  8.  

 
label.common.footer.alt.autozoneLogo