Download CAUTION: Since the engine is not free-wheeling, timing procedures must be followed exactly or piston and valve damage may occur. 1. Remove the engine front cover (6019). For additional information, refer to Engine Front Cover in this section. 2. NOTE: Procedure is for either RH or LH ignition coil (12029); LH ignition coil is shown. Disconnect the ignition coil electrical connector and remove the retaining bolt. 3. Tilt the coil away from the fuel injection supply manifold. 4. Remove the ignition coil. 5. NOTE: Remove any foreign material from the spark plug wells with compressed air before removing the spark plugs. Remove the spark plugs. 6. Position the lobe of the camshaft up. 7. Install the special tool between the valve spring coils to prevent valve stem seal damage. 8. NOTE: The roller followers are positional. Mark the followers for installation in their original locations. NOTE: The last three roller followers must be removed with special service tool 303-581. Use the special tool to compress the valve springs and remove the camshaft roller followers. 9. Remove the crankshaft sensor ring from the crankshaft. 10. Remove the bolts and the LH timing chain tensioner. 11. Remove the bolts and the RH timing chain tensioner. 12. Remove the LH and RH timing chain tensioner arm from the dowel pins. 13. Remove the timing chains and crankshaft sprocket. 14. Remove the timing chain guides. 1. Remove the bolts. 2. Remove the LH timing chain guide. 3. Remove the bolts. 4. Remove the RH timing chain guide. Installation 1. CAUTION: Timing chain procedures must be followed exactly or damage to valves and pistons will result. CAUTION: Do not compress the ratchet assembly. This will damage the ratchet assembly. Compress the tensioner plunger, using an edge of a vise. 2. Using a small screwdriver or pick, push back and hold the ratchet mechanism.