Overhead setting is only required at the interval specified in the appropriate Operation and Maintenance I Owners
manuals, or when engine repairs cause removal of the rocker levers and/or loosening of the adjusting screws.
Excessive valve lash prior to a repair or scheduled adjustment can indicate:
โข Incorrect valve set from a previous repair
โข Worn valve stems, crossheads, push rods, and/or rocker levers.
Loose rocker lever lash and the need to frequently reset the valve clearance can also indicate camshaft lobe wear
or tappet wear. If an inspection of the rocker levers, valve stems, crossheads, and push rods do not show wear,
tappet and/or camshaft lobe wear can be suspected. Refer to Procedure 001-008 in Section 1. Refer to Procedure
004-015 in Section 4.