Removal & Installation
- If equipped with air suspension, the air suspension switch, must be turned to the OFF position before raising the vehicle.
- Properly relieve the fuel system pressure.
- Drain the engine oil
Remove or disconnect the following:
NOTEThe front lower bolt on the power steering pump will not come all the way out.
Negative battery cable
- Rotate the crankshaft counterclockwise no more than 45 degrees from Top Dead Center (TDC) to ensure that all pistons are below the top of the engine block deck face.
- Install a valve spring compressor under the camshaft and on top of one of the valve spring retainers.
- Install Valve Spring Spacer T91P-6565-AH between the valve spring coils. Be sure that the valve being compressed is on its base circle. Compress the valve spring and remove the rocker arm. Repeat the procedure until all rocker arms are removed.
If required, pull the lash adjusters out of their bores in the cylinder head. Note their locations; they must be installed in the same bore they were removed from.
NOTEDo not mix the camshaft bearing caps. Note the camshaft bearing cap locations for installation.
- To remove each camshaft, unfasten the 14 bolts retaining the camshaft bearing caps (cluster assemblies) to the cylinder head. Tap upward on the camshaft bearing caps at points near the upper bearing halves and gradually lift the camshaft bearing cap clusters from the cylinder head.
- Repeat the removal procedure for the opposite cylinder head.
- Remove the camshaft straight upward to avoid bearing damage.
Clean and inspect the camshafts and related components for unusual wear or damage.
- Clean and inspect the cylinder head covers, engine front cover and cylinder head sealing surfaces.
- Apply clean engine oil to the camshaft journals and lobes. Position the camshafts on the cylinder heads.
Install and seat the camshaft bearing cap cluster assemblies. Install and hand start the retaining bolts. Tighten the camshaft cluster retaining bolts in sequence to 89 inch lbs. (10 Nm). Be sure to tighten each camshaft bearing cap cluster individually.
NOTEEach camshaft bearing cap cluster assembly is tightened individually.
- Loosen the camshaft bearing cap cluster retaining bolts approximately 2 turns or until the heads of the bolts are free. Tighten all bolts, again in sequence, to 89 inch lbs. (10 Nm).
Repeat the camshaft bearing cap installation for the opposite cylinder head.
NOTEThe camshafts should turn freely but with a slight drag.
Check camshaft end-play as follows:
- Step 1: Install a dial indicator on the front of the engine. Position it so the indicator foot is resting on the camshaft sprocket bolt or the front of the camshaft.
- Step 2: Push the camshaft toward the rear of the engine and zero the dial indicator.
- Step 3: Pull the camshaft forward and release it. Specified end-play is 0.0901-0.006 inch (0.025-0.190mm).
- Step 4: If end-play is too tight, check for binding or foreign material in the camshaft thrust bearing. If end-play is excessive, check for worn camshaft thrust plate and replace the cylinder head, as required.
- Step 5: Remove the dial indicator.
- If removed, install the lash adjusters in their original positions.
- If necessary, install Camshaft Positioning Tools T92P-6256-A on the flats of the camshafts and install the spacers and camshaft sprockets. Install the bolts and washers and tighten to 30 ft. lbs. (40 Nm), then tighten an additional 90 degrees.
- Install a valve spring compressor under the camshaft and on top of the valve spring retainer.
- Install Valve Spring Spacer T91P-6565-AH between the valve spring coils. Be sure that the valve being compressed is on its base circle. Compress the valve spring and install the rocker arm. Repeat the procedure until all rocker arms are installed.
Rotate the crankshaft clockwise 45 degrees to position the crankshaft at Top Dead Center (TDC).
NOTEThe crankshaft must only be rotated in the clockwise direction and only as far as TDC.
Install or connect the following:
- Apply silicone sealer to the crankshaft keyway
Install the crankshaft pulley and tighten the bolt as follows:
- Step 1: Tighten to 66 ft. lbs. (90 Nm).
- Step 2: Loosen one complete turn.
- Step 3: Tighten to 37 ft. lbs. (50 Nm).
- Step 4: Tighten an additional 90 degrees.
Install or connect the following:
Engine oil pan
- Fill the engine cooling system.
- Fill the crankcase.
- If equipped with air suspension, turn the air suspension switch to the ON position.
- Start the engine and check for leaks.
- Road test the vehicle and check for proper engine operation.