4 speed gearbox

[fig]

I've got my gearbox on the bench while doing a rear main seal and I have a question about weather it's functioning properly. Rotating the input shaft by hand while pulling on it causes it to bind. When I push on the shaft or put pressure on it radially while turning it, things seem fine. No notchy-ness in the bearing is detected when its turned, even when it's binding. Waht is causing this?

In use things seem fine although 4th gear has a distinct wine which may just be the helical gear noise that's often talked about, I have nothing to compare it too so don't know if the sound is a clue.

Can I run this box or does it need service? Thanks.
DF

'73 R75/5

[Duane Ausherman]

I suggest that you need to perform a bench test to see if it does the shifting properly. Did you drain the oil to see if it is clean?

[Ken in Oklahoma]

I suggest that you need to perform a bench test to see if it does the shifting properly. Did you drain the oil to see if it is clean?

Duane talks about how to do a bench test on his website, IIRC.


Ken

[fig]

When this box was in the bike the shifting seemed fine, no noticeable problem. It would come out of third gear occasionally when cold, but hasn't done that for a while, mostly cause I shift more deliberately now. I did notice while pushing and pulling on the input shaft that there's some slack in there, it'll move forward and back just a bit.

I'll go through the bench test next to see what else I can find out.

DF