jd trans

[ragsflh]

mainshaft bushing i am replacing.what clearance does bushing to drive gear need to be sized too.this is on a 1928 transmission.

[Tommo]

The factory says .003, Three Thou. (see service bulletin number 79)
I tend to be generous here as the oil to lubricate the main shaft bush and the clutch hub rollers needs to get out here to do its job.
I'm happy with anything up to a tight .005 thou but that's just a personal thing as my bike has a sidecar on it and doesn't leak much oil out there.
A solo on the jiffy stand is a different thing and will leak some oil when leaned over if the gearbox is filled up correctly and you've been generous with the clearance.
Hope this helps and I apologize for not seeing your post sooner.