REMOVAL & INSTALLATION
See Figure 1
The following procedure covers camshaft removal and installation with the cylinder head on or off the engine. If the cylinder head has been removed start at Step 9.
- Remove the air cleaner assembly and disconnect the negative battery cable. Drain the cooling system.
- Remove the spark plug wires from the plugs, disconnect the retainer from the valve cover and position the wires out of the way. Disconnect the rubber vacuum lines as necessary.
- Remove all drive belts. Remove the alternator mounting bracket-to-cylinder head mounting bolts, and position the bracket and alternator out of the way.
- Disconnect and remove the upper radiator hose. Disconnect the radiator shroud.
- Remove the fan blades and water pump pulley and fan shroud. Remove the valve cover and timing belt outer cover.
- Align the engine timing marks at TDC. Remove the timing belt.
- Raise the front of the car and support it on jackstands. Remove the front motor mount bolts. Disconnect the lower radiator hose from the radiator. Disconnect and plug the automatic transmission cooler lines, if so equipped.
- Position a piece of wood on a floor jack and raise the engine carefully as far as it will go. Place blocks of wood between the engine mounts and crossmember pedestals.
- Remove the cam followers (rocker arms) as described earlier in this section.
- Remove the camshaft sprocket and belt guide using a suitable puller. Remove the front oil seal with a sheet metal screw and slide hammer or special seal remover tool.
- Remove the camshaft retainer located on the rear mounting stand, by unfastening the two bolts or screws.
- Remove the camshaft by carefully withdrawing it toward the front of the engine. Caution should be used to prevent damage to the cam bearings, lobes and journals.
- Check the camshaft journals and lobes for wear. Inspect the cam bearings. If they are worn, the cylinder head must be removed for new bearings to be installed by a machine shop.
- Install the camshaft. Caution should be used to prevent damage to the cam bearings, lobes and journals. Coat the camshaft with heavy SG engine oil or a suitable prelube before sliding it into the cylinder head.
- Install the camshaft retainer located on the rear mounting stand.
- Install a new front oil seal.
- Install the camshaft sprocket and belt guide. Apply a coat of sealer or Teflon® tape to the camshaft sprocket bolt before installation.
- Install the cam followers as described earlier in this section.
- Remove the blocks of wood between the engine mounts and crossmember pedestals, and lower the engine onto the mounts.
- Lower the front of the car.
- Install the front motor mount bolts.
- Connect the lower radiator hose at the radiator.
- Connect the automatic transmission cooler lines, if applicable.
- Align the engine timing marks at TDC.
- Install the timing belt.
- Install the timing belt outer cover and valve cover.
- Install the fan blades and water pump pulley and fan shroud.
- Connect and install the upper radiator hose.
- Install the alternator and mounting bracket on the cylinder head.
- Install all drive belts.
- Install the spark plug wires on the plugs.
- Connect the plug wires to the retainer on the valve cover.
- Connect the rubber vacuum lines as necessary.
- Fill the cooling system.
- Install the air cleaner assembly.
- Connect the negative battery cable.
- Remove the cylinder head. Refer to Cylinder Head Removal & Installation procedures, in this section.
- Remove the cylinder front cover, timing chain and sprockets as outlined previously.
- Disconnect and remove the radiator, condenser and grille. Remove the gravel deflector.
- Using a magnet, remove the valve lifters and keep them in order so that they can be installed in their original positions.
- Remove the camshaft thrust plate and remove the camshaft by pulling it from the front of the engine. Use care not to damage the camshaft lobes or journals while removing the cam from the engine.
- Before installing the camshaft, coat the lobes with engine assembly lubricant and the journals and all valve parts with heavy oil. Clean the oil passage at the rear of the cylinder block with compressed air.
V6 and V8 Engines
See Figures 2, 3 and 4
- Remove or reposition the radiator, A/C condenser, if so equipped, and grille components, as necessary, to provide clearance for camshaft removal.
- Remove the cylinder front cover and timing chain as previously described in this section.
- Remove the crankcase ventilation valve and tubes from the valve rocker covers. Remove the EGR cooler, if so equipped.
- Remove the valve covers. On some engines, it may be necessary to remove the intake manifold and other related parts.
- Loosen the rocker arm fulcrum bolts and rotate the rocker arms to the side.
- Remove the valve pushrods and identify them, so that they can be installed in their original positions.
- Remove the valve lifters and place them in a rack, so that they can be installed in their original bores.
- Remove the camshaft thrust plate or button and spring, and carefully remove the camshaft by pulling toward the front of the engine. Be careful not to damage the camshaft bearings.
- Before installing, oil the camshaft journals with heavy SG engine oil and apply Lubriplate® or equivalent to the lobes. Carefully slide the camshaft through the bearings.
- Install the camshaft thrust plate with the groove towards the cylinder block.
- Lubricate the lifters with heavy SG engine oil or suitable prelube and install in their original bores.
- Apply Lubriplate® or equivalent to the valve stem tips and each end of the pushrods. Install the pushrods in their original positions.
- Lubricate the rocker arms and fulcrum seats with heavy SG engine oil and position the rocker arms over the push rods.
- Install all other parts previously removed.
- Fill the crankcase and cooling system and adjust the timing.
See Figure 5
Clean the camshaft using a safe solvent, and clean all oil grooves. Visually inspect the cam lobes and bearing journals for excessive wear. If a lobe is questionable, check all lobes and journals with a micrometer.
Measure the lobes from nose to base (measurement A) and again from side to side (measurement B). The lift is determined by subtracting the second measurement from the first. If all exhaust lobes and all intake lobes are not identical, the camshaft must be reground or replaced. Measure the bearing journals and compare to specifications. If a journal is worn there is a good chance that the cam bearings are worn too, requiring replacement.
If the lobes and journals appear intact, place the front and rear cam journals in V-blocks and rest a dial indicator on the center journal. Rotate the camshaft to check for straightness; if deviation exceeds 0.001 in. (0.025mm), replace the camshaft.
See Figure 6
This procedure must be performed with the engine removed from the vehicle.
- Remove the camshaft, flywheel and crankshaft, following the appropriate procedures. Push the pistons to the top of the cylinder.
- Remove the camshaft rear bearing bore plug. Remove the camshaft bearings with Tool T65L-6250-A or equivalent.
- Select the proper sized expanding collet and back-up nut and assemble on the mandrel. With the expanding collet collapsed, install the collet assembly in the camshaft bearing and tighten the back-up nut on the expanding mandrel until the collet fits the camshaft bearing.
- Assemble the puller screw and extension (if necessary) and install on the expanding mandrel. Wrap a cloth around the threads of the puller screw to protect the front bearing or journal. Tighten the pulling nut against the thrust bearing and pulling plate to remove the camshaft bearing. Be sure to hold a wrench on the end of the puller screw to prevent it from turning.
- To remove the front bearing, install the puller from the rear of the cylinder block.
- Position the new bearings at the bearing bores, and press them in place with tool T65L-6250-A or equivalent. Be sure to center the pulling plate and puller screw to avoid damage to the bearing. Failure to use the correct expanding collet can cause severe bearing damage. Align the oil holes in the bearings with the oil holes in the cylinder block before pressing bearings into place.
- Install the camshaft rear bearing bore plug.
- Install the camshaft, crankshaft, flywheel and related parts, following the appropriate procedures.
- Install the engine in the car, following procedures described earlier in this section.