Inspecting The Timing Chain
Chain Guides (4.7L)
Check for grooves. Replace parts if grooves are more than 0.039 in. (1 mm) deep.Timing Chain Deflection
3.9L, 5.2L, 5.9L, & 8.0L Engines
- If a chain tensioner is fitted, it must be removed before this check is carried out.
- Position a scale (ruler or straightedge) next to the timing chain to detect any movement in the chain.
- Place a torque wrench and socket on the camshaft sprocket attaching bolt. Apply 30 ft. lbs. (41 Nm) of torque if the cylinder heads are installed on the engine, or 15 ft. lbs. (20 Nm) if the cylinder heads are removed, and rotate the bolt in the direction of crankshaft rotation in order to remove all slack from the chain.
- While applying torque to the camshaft sprocket bolt, the crankshaft should not be allowed to rotate. It may be necessary to block the crankshaft to prevent rotation.
- Position the scale over the edge of a timing chain link and apply an equal amount of torque in the opposite direction. If the movement of the chain exceeds 1 / 8 in. (3.175mm), replace the chain.
- If camshaft endplay exceeds 0.010 in., install a new thrust plate. It should be 0.002-0.006 in. with the new plate.