REMOVAL & INSTALLATION
See Figures 1, 2, 3 and 4
This engine uses a Dual Over Head Camshaft (DOHC) 4-valves per cylinder crossflow aluminum cylinder head. The valves are actuated by roller cam followers which pivot on stationary hydraulic valve lash adjusters. Care must be taken to ensure all valve timing marks align after cylinder head and valvetrain service.
- Properly relieve the fuel system pressure.
- Disconnect the negative battery cable.
- Label and disconnect the spark plug wires from the spark plugs.
- Remove the ignition coil pack and spark plug wires.
- Remove the cylinder head cover retaining fasteners and remove the cylinder head cover from the cylinder head. Discard the old cylinder head cover gasket.
- Remove the ground strap.
- Remove the timing belt covers, timing belt and camshaft sprockets.
- Take note that the camshaft bearing caps are numbered for correct location during installation. Remove the outer bearing caps first.
- Loosen, but do not remove, the camshaft bearing cap retaining fasteners in the correct sequence. Perform this step on one camshaft at a time.
- Tag the camshafts for intake and exhaust, if they are to be reused, for later installation. The camshafts are not interchangeable. Remove the camshaft bearing caps and the camshafts.
- Remove the camshaft followers. Any components that are to be reused must be installed in their original locations. Use care to identify and mark the positions of any removed valvetrain components so they may be reinstalled correctly.
- Inspect the camshaft bearing oil feed holes in the cylinder head for clogging. Inspect the camshaft bearing journals for wear or scoring. Check the cam surface for abnormal wear and damage. A visible worn groove in the roller path or on the cam lobes is cause for replacement.
- Thoroughly clean the camshafts and related parts.
The camshaft end-play should be checked using the following procedure:
- Oil the camshaft journals and install the camshaft WITHOUT the cam follower assemblies. Install the rear cam caps and tighten to 250 inch lbs. (28 Nm).
- Carefully push the camshaft as far rearward as it will go.
- Set up a dial indicator to bear against the front of the camshaft (the sprocket end). Zero the indicator.
- Move the camshaft forward as far as it will go. Read the dial indicator. End-play specification is 0.002-0.010 in. (0.05-0.15mm).
- If excessive end-play is present, inspect the cylinder head and camshaft for wear; replace if necessary.
- If satisfied with the fit and condition of the camshafts, remove the camshafts for installation of the cam followers.
- The hydraulic valve lash adjusters are inside the roller cam followers. Ensure they are clean, well-lubricated with clean engine oil and properly positioned. Install the cam followers in their original positions on the hydraulic lash adjuster and valve stem.
- Lubricate the camshaft bearing journals and cam followers with clean engine oil and install the camshafts. Install right and left camshaft bearing caps No. 2 through No. 5 and right side No. 6. Tighten the M6 fasteners to 105 inch lbs. (12 Nm) in correct sequence.
- Apply Mopar® Gasket Maker or equivalent sealer to the No. 1 and left side No. 6 bearing caps. Install the bearing caps and tighten the M8 fasteners to 250 inch lbs. (28 Nm). The end caps must be installed before the seals may be installed.
- Install the camshaft end seals.
- Install the camshaft sprockets, if removed. Install the timing belt using care to be sure all timing marks are properly aligned. Install the timing belt covers.
- Clean the cylinder head cover and cylinder head gasket rails (mating surfaces). Make certain the rails are flat.
- Install new cylinder head cover gaskets. Use care; DO NOT allow oil or solvents to contact the timing belt as they can deteriorate the rubber and cause tooth skipping. Apply Mopar Silicone Rubber Adhesive Sealant, or equivalent, at the camshaft cap corners and at the top edge of the 1 / 2 round seal.
Inspect the spark plug well seals for cracking and/or swelling, and replace if necessary.
Install the cylinder head cover assembly to the head and tighten the fasteners in sequence using the following three substeps:
- Tighten all cylinder head cover fasteners to 40 inch lbs. (4.5 Nm).
- Tighten all fasteners to 80 inch lbs. (9 Nm).
- Tighten all fasteners to 105 inch lbs. (12 Nm).
- Install the ignition coil pack and connect the spark plug wiring to the correct spark plugs. Tighten the coil pack retaining fasteners to 105 inch lbs. (12 Nm).
- Reconnect the ground strap.
- Ensure all vacuum lines and remaining wiring have been reconnected.
To remove any dirt particles that may have fallen in the engine, an oil and filter change is recommended.
- Connect the negative battery cable and test run the vehicle. Check for leaks and for proper operation.
See Figures 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17 and 18
Working on any engine, but especially overhead camshaft engines, requires much care be given to valve timing. It is good practice to set the engine up at TDC No. 1 cylinder firing position. Verify that all timing marks on the crankshaft and camshaft sprockets are properly aligned before removing the timing belt and beginning camshaft service. This serves as a point of reference for all work that follows. Valve timing is very important and engine damage will result if the work is incorrect.
- Disconnect the negative battery cable.
- Remove the air cleaner assembly. Disconnect and label the spark plug wires.
- Remove the accessory drive belts, if necessary.
- Move away any wiring harnesses for easier access to the rear valve cover. Disconnect and label any vacuum hoses required for easier removal of the valve covers.
- Remove the valve covers from the vehicle.
- Remove the timing belt. Remove the camshaft timing belt sprockets.
- Install auto lash adjuster retainers MD998443 or equivalent on the rocker arms.
- If removing the right side (front) camshaft, remove the distributor adapter.
- Remove the camshaft bearing caps, but do not remove the bolts from the caps.
- Remove the rocker arms, rocker shafts and bearing caps, as an assembly.
Use care not to mix rocker arms and shafts. The oil holes are different in the shafts and each must be returned to its original location or the engine overhead will not be lubricated.
- Remove the camshaft from the cylinder head.
- Inspect the bearing journals on the camshaft, cylinder head and bearing caps.
- Clean all parts well. Pay particular attention to the oil feed holes in the cylinder head, checking for clogging. If the camshafts are to be reused, check with a micrometer. Measure the cam height and replace if out of limit. Standard value is 1.624 in. (41.25mm) and wear limit is 1.604 in. (40.75mm).
- Lubricate the camshaft journals and camshaft with clean engine oil and install the camshaft in the cylinder head.
- Align the camshaft bearing caps with the arrow mark (depending on cylinder numbers) and in numerical order.
- Apply sealer at the ends of the bearing caps and install the assembly.
- Tighten the bearing cap bolts, in the following sequence: No. 3, No. 2, No. 1 and No. 4 to 85 inch lbs. (10 Nm).
- Repeat the sequence, increasing torque to 180 inch lbs. (20 Nm).
- Install the distributor adapter, if it was removed.
- Remove the lash adjuster retainers. Install the camshaft timing belt sprockets and timing belt.
- Install the valve covers and new gaskets. Tighten the valve cover retaining bolts to 88 inch lbs. (10 Nm).
- Reconnect all vacuum hoses that were removed during the removal procedure. Be sure they are all reconnected to the correct vacuum lines.
- Position the wiring harnesses back to their original locations. Install the accessory drive belts and adjust to the proper tension.
- Reconnect the spark plug wires to the correct spark plugs.
- Install the air cleaner assembly. Reconnect the negative battery cable.
- Run the engine and check for leaks and proper engine operation.
See Figure 19
- Relieve the fuel system pressure. Disconnect the negative battery cable.
- Remove the engine from the vehicle. Remove the intake manifold, cylinder heads, timing chain cover and timing chain from the engine.
- Remove the rocker arm and shaft assemblies.
- Label and remove the pushrod and lifters.
- Remove the camshaft thrust plate.
- Install a long bolt into the front of the camshaft to facilitate its removal. Remove the camshaft being careful not to damage the cam bearings with the cam lobes.
- Install the camshaft to within 2 in. of its final installation position.
- Install the camshaft thrust plate and two bolts. Tighten the bolts to 10 ft. lbs. (12 Nm).
- Place both camshaft and crankshaft gears on the bench with the timing marks on the exact imaginary center line through both gear bores as they are installed on the engine. Place the timing chain around both sprockets.
- Turn the crankshaft and camshaft so the keys line up with the key ways in the gears when the timing marks are in proper position.
- Slide both gears over their respective shafts and use a straight edge to check timing mark alignment.
- Measure camshaft end-play. If not within specifications, replace the thrust plate.
- If the camshaft was not replaced, lubricate and install the lifters in their original locations. If the camshaft was replaced, new lifters must be used.
- Install the pushrods and rocker shaft assemblies.
- Install the timing chain cover, cylinder heads and intake manifold.
- Install the engine in the vehicle.
- When everything is bolted in place, change the engine oil and replace the oil filter.
If the camshaft or lifters have been replaced, add 1 pint of Mopar crankcase conditioner, or equivalent when replenishing the oil to aid in break in. This mixture should be left in the engine for a minimum of 500 miles and drained at the next normal oil change.
- Fill the radiator with coolant.
- Connect the negative battery cable, set all adjustments to specifications and check for leaks.
- Inspect the camshaft bearing journals for wear or damage.
- Inspect the cylinder head and check oil return holes.
- Check the tooth surface of the distributor drive gear teeth of the right camshaft for wear or damage.
- Check both camshaft surfaces for wear or damage.
- Remove the distributor drive adaptor seal.
- Check camshaft lobe height and replace if out of limit. Standard value is 1.61 in. (41mm).