primary knock

[fdrdr1]

Been tryin to chase down a knock from the primary for a while. Pulled the inner/outer primaries and found no problem. Took a look at the stator and found no issues there either. Button everything back up and take it for a spin and the knock is still there. It is just tough to pinpoint because when ridin and listening to the right side it sometimes sounds like it may be comin from the tranny, other times from the left front of the primary. Only upon deacceleration though - when I pull in the clutch the knock disappears. Not sure where to go from here - any ideas? Thanks

[Porkchop]

What year/model ? 

[fdrdr1]

91 FXR - Evo

[Hillside Motorcycle]

How many miles on the lower end??

[fdrdr1]

45K - did the top end about 5k ago

[Traveler733]

Check the bellville spring washer in the clutch hub. (it's like a wavy washer, more than an actual spring.)  It needs to keep a little pressure on the end of the trans. mainshaft. The shaft is splined and the clutch basket can have excessive end play if this springy washer is missing, or the snap ring holding it in the hub has been sheared or loosened. This can cause a knocking sound.

[fdrdr1]

Traveler733 - When I had the clutch assembly off I did not notice a spring or washer - I checked the HD manual and it does not show anything that fits that description. I will pull it off again and take another look - Thanks

[Evo160K]

My clutch hub bearing (1990 fxstc) went bad recently.  It sounded like a bottom end problem.  Also had a lifter go a few months latter that I swear was the bottom end.  It didn't sound like a lifter and I've had six go out over the 215,000 miles.

[Traveler733]

The manual does NOT show the bellville washer. It's in the clutch hub. (center piece. It would be what the clutch nut pulls against to tighten the clutch assembly on the shaft, to prevent the clutch assembly from sliding back  forth (end play)
If you have the clutch apart. (as in changing discs)   It's the part that the "L " ring and outer snap ring holds the hub to the basket. Harley doesn't show this as a separate part. They want you to buy the whole hub assembly. If you remove the bellvile washer, it awful difficult to reassemble correctly, as it's in the under tension. When you tighten the mainshaft nut, it pre-loads this wave (bellvile washer) to stop clutch assembly end play.