PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS), INCLUDING
LUBRICATION INSTRUCTIONS Continued
ITEM TO BE
c. The sound produced from a good spline drive
coupling is muffled, and can be heard as the
engine is cranking. The sound is muffled
because the external spline on the spline drive
ring is nylon coated. When the nylon coating,
which is only 13 to 20 thousandths of an inch
thick, on the spline drive ring is good, it will
mate tightly with the engines internal spline
teeth and produce a muffled sound.
The sound produced from a worn-out spline
drive coupling is a very distinct metallic
clanking sound that can be easily heard as the
engine is cranking. When the nylon coating on
the spline drive ring is worn-out, it engages in a
metal to metal backlashing with the flywheels
internal spline teeth which are uncoated. This
causes the metallic clanking sound.
a. The second type of inspection is the manual
Fuel cut-off control at drivers position
must be pulled all the way out to prevent
engine from starting. Personnel could be
injured or killed if engine starts during
this PMCS check.
b. Loosen the three wing nuts and clamps to
remove the engines rear access panel from the
crew compartment. This will access the
engines variable drive assembly pulley.
c. The pulley has three jacking bolt holes with 3/
8 course thread. Hand tighten two 3/8 by 3
long bolts into the jacking holes.