Im investigating the grinding noise on my trailboss. All external parts are fine (drive chain and sprockets). I splint the gear box and found everything in acceptable condition. (There were shavings on the drain plug) What I did find is excessive slack in the silent chain. Is it possible for that chain to stretch that much? Clearly it was rubbing on the bottom of the gear box. It appears it is about 1/2 link too long now. Thanks for any input!

 

Replace the silent chain and the two gear case seals.You'll see a difference on the new one as far as slack.This is the most common wear item in chain driven gear cases. Also check that the gear lugs and teeth are ok and the bearings turn smooth without any roughness.http://www.cyclepartswarehouse.com/f...2003&fveh=5623

 

That's route I was going to take but just wanted confirm with someone else. Thanks for the help