Vibration complaints?    Engine noise?    Are you sure that it is the engine?

Some of the noises found, defined as either Top or Bottom End related,

were eliminated by adjusting the primary chain correctly. Check the primary

chain's adjustment before attempting to diagnose engine noise.

Complaints of engine noise or vibration are often traced back to a loose

compensating nut in the primary drive. Use a stethoscope to isolate the source,

and eliminate obvious external culprits. If it appears to be in the primary housing,

first check for a loose compensating nut.

If loose, disassemble the parts and look for worn surfaces indicating poor

clamp load and a diminished stack height. Replace any damaged

components. When reassembling, clean the threads on both the shaft and

nut, prime the threads, loctite parts with 262 threadlocker and torque to 150-

165 ft-lbs.

If the nut seems tight there may be a stack up issue preventing it from

achieving full clamp load. Try adding a 24033-70 shim under the head of the

compensating nut (p/n 40392-91) and re-assemble as described above.