Noisy gearboxes

[daveg]

I got a chance to dismantle the original Nippy gearbox today. I found these numbers - Lay shaft gear cluster G760, 1st motion shaft and 3rd gear cog 351S. The gears and synchros all look to be in good condition

The lay shaft is grooved.

   

I don't know what the ring between the gear and the synchro ring is called but it is loose and can be moved about 2mm. It is hard to see in the picture but the synchro is not flush with the back of the gear. Can it be heated and pressed further?

   

There are marks at a funny angle on the lay shaft bearing face as if it has been filed.

   

The lay shaft cluster front bearing is worn but fairly smooth. Is the welded on gear normal?

   

I am going to fit new roller bearings, clean up the lay shaft bearing faces and reduce the end float by fitting a shim behind the front bush and see what difference it makes