CAMSHAFT & BEARINGS (IN BLOCK)
DESCRIPTION
The nodular iron camshaft is mounted in the engine block and supported with four steel backed aluminum bearings . A thrust plate, located in front of the first bearing, is bolted to the block and controls the camshaft end play.
OPERATION
The camshaft is driven by the crankshaft through a timing chain and sprockets. The camshaft has precisely machined (egg-shaped) lobes to provide accurate valve timing and duration.REMOVAL
1. Remove the radiator and cooling fans from the vehicle.
2. Remove the cylinder heads (Refer to 9 - ENGINE/CYLINDER HEAD - REMOVAL).
3. Remove the timing chain and camshaft sprocket (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT/CHAIN AND SPROCKETS - REMOVAL).
4. Remove the yoke retainer (1).
5. Remove the hydraulic lifters (4) (Refer to 9 - ENGINE/ENGINE BLOCK/HYDRAULIC LIFTERS (CAM IN BLOCK) - REMOVAL). Identify each tappet for reinstallation in original location.
6. Remove camshaft thrust plate (1).
NOTE: Slowly remove the camshaft from the engine taking precautions not to damage the camshaft bearings.
7. Install a long bolt into front of camshaft to facilitate removal of the camshaft.
8. Carefully remove the camshaft,
NOTE: The camshaft bearings are serviced with the engine block.
INSPECTION
1. Check the cam lobes and bearing surfaces for abnormal wear and damage . Replace camshaft as required.
NOTE: If camshaft is replaced due to lobe wear or damage, always replace the lifters.
2. Measure the lobe actual wear (unworn area - wear zone = actual wear) and replace camshaft if out of limit. Standard value is 0.0254 mm (0.001 in.), wear limit is 0.254 mm (0.010 in.).
INSTALLATION
1. Lubricate camshaft lobes and camshaft bearing journals with engine oil .
2. Install a long bolt into the camshaft to assist in the installation of the camshaft .
3. Carefully install the camshaft in engine block.
4. Install camshaft thrust plate and bolts . Tighten to 12 N·m (105 in. lbs.) torque.
5. Measure camshaft end play. (Refer to 9 - ENGINE - SPECIFICATIONS) If not within specifications, replace thrust plate.
6. Install the timing chain and sprockets. (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT/CHAIN AND SPROCKETS - INSTALLATION)
NOTE: When camshaft is replaced, all of the hydraulic lifters must be replaced.
7. Install the hydraulic lifters with lubrication hole in the upward position (Refer to 9 - ENGINE/ENGINE BLOCK/HYDRAULIC LIFTERS (CAM IN BLOCK) - INSTALLATION).
8. Install the timing chain cover. (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) - INSTALLATION)
9. Install the cylinder heads. (Refer to 9 - ENGINE/CYLINDER HEAD - INSTALLATION)
10. Install the cylinder head covers. (Refer to 9 - ENGINE/CYLINDER HEAD/CYLINDER HEAD COVER(S) - INSTALLATION)
11. Install the lower and upper intake manifolds. (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD - INSTALLATION)
12. Install the radiator and cooling fan.