Noisy Rebuilt Comet Burman Gearbox

Matty

Well Known and Active Forum User
VOC Member
In 1957 my Comet Gearbox shed a tooth and did a lot of damage.

I had no money then, so replaced the damaged gears, had the casing welded up, straightened the mainshaft on a flypress and put it together again to sort out properly later!!

This Winter 53 years later, having used the bike continuously since and thinking it was a bit noisy I stripped the box and found that the layshaft was very bent and consequently its plain bush bearings shot - though it still all worked fine.

Replaced all bearings, the layshaft and both 3rd gears (because the dogs looked worn in the larger gear). Filled the box with 800gms of semi liquid grease for Burman gearboxes bought from Draganfly and assumed it would now all be nice and quiet.

If anything it whines even more in 3rd than it did before, though again it works perfectly.

I get the impression ( though it's difficult to be sure) that the whining is less for a few seconds after the bike has been standing for a while - so it could be the grease is squeezed off the gears and is not being picked up onto the gears again - but it is pretty liquid, does flow slowly and is much thinner than the LM grease which I had always used before.

Will the new gears run in with time or should I try another lubricant and what is the easiest way to get the old grease out withot stripping the gearbox if I have to change the grease please?

Anone have any ideas please.

Alan Matthews​
 

chankly bore

Well Known and Active Forum User
Non-VOC Member
stick half a cup of 30 weight oil in it---works for me! Also check that the clutch roller race is lubricated if this doesn't work.You don't need to get the grease out.
 
Top