Motorcycle Repair: transmission, shaft bearing, shift fork

Question
Bill:

I am repairing a '85 CMX 250 Rebel. What would cause a rattle or "rocks in the box" sound in the transmission while in third gear only. Shift out of third, or into any other gear, and it's noise free. I suspect a sloppy shift fork. Your help would be appreciated.

Carl

Answer
Carl, third gear only could be a broken gear tooth, gear engagement dogs and/or shift fork not engaging the gear all the way. Shift drum could have a damaged track, too.
A shaft bearing would make noise all the time.

Gotta come apart to see what's what in there. Drain the oil and look for metal parts/particles.

Bill Silver