R100 Transmission "Squawk"

[tpfeffer]

I have a '83 R100RS with about 33,000 on the odometer that I bought 4 years ago. There is a sound coming from the transmission area, more from the rear than the front. I used a piece of hose to isolate the sound. I don't know how else to describe the noise; it sounds like a squawk.

 

I hear the noise only after the transmission is fully warmed up. It doesn't seem to make any difference if the transmission is in neutral or in gear with the clutch pulled in. The noise doesn't stop or change appreciably when the clutch lever is pulled in. I don't hear the noise above the wind and engine noise at speed so cannot say for sure if it changes with engine speed when moving.

 

I regularily change transmission fluid; the last time about 1000 miles ago when I used Valvoline dino 80w-90 GL5 gear lube.

 

I lubricated the transmission splines with BMW #10 grease about 2000 miles ago by moving the swing arm and transmission back in the frame.

 

I do have a minor rear main seal leaking, but it is just a few drops on stopping and never has affected the engine oil level. The clutch engagement is normal.

 

Are they any ideas on what the squawk can be?