Belt drive oil leak fix

If you have some oil leakage with your belt drive and you've already installed the pushrod oil seal then you probably have oil leaking through the sleeve gear at the bronze bushing and making a mess. An easy fix is a 1/8" cross section Oring with 1" OD doubled up with a 1/16" cross section oring with 1-1/16" OD as in the photo below.



There might be other ways to go it but this is very easy. I tried just the 1/8" thick Oring but there wasn't enough tension against the sleeve gear.

Given that the mainshaft and the sleeve gear frequently spin at different speeds I would think that the seals would be short lived, can't say for sure, just thinking. Certainly an idea worth pursuing; why not countersink the bronze bush (or bushes, as in Mk3 type) and fit a seal just inside of the sleeve gear, maybe a few shims between the sleeve gear's end and the basket retaining circlip? Still have the different speeds of the shaft/sleeve gear, but, maybe a modicum of gear oil lubrication to extend its' life??

I put a layer of tri-bond in the teeth of the countershaft sprocket, this has been effective in keeping gear oil from leaking through the output shaft bearing, especially useful if you like to park your Norton on its side stand, or take extended left hand sweepers.

Tap in new sleeve bushings every tranny teardown I say. 850 type. I try to eliminate O rings. Columbia space Shuttle comes to mind. Not as serious of course. :shock:

What did you use for a metal cap shown behind the clutch retainer circlip?

RoadScholar
Time will tell with the oring wear. I didn't see any wear when I just used one 1/8" thick oring - but there wasn't enough side tension so the 1/16" thick oring is there to seal between the 1/8" oring and the sleeve gear.

I also had the leak though the main output shaft bearing. I solved this problem with:

1/32x 1-1/4 ID ” O ring between sleeve gear & brg. Sprocket ring OD increased to 44mm and 3mm wide chamfer added to ID for 1” ID Oring to even out crush on 0ring (minor machining - can't remember exactly).

Other oring fixes are listed below:

3/32 x 1-1/8 ID sump plug with aluminum spacer that goes around the o ring and is about .010” shorter than oring.
Tranny kick shaft – use wooden shaft to force in a oversize 1/8x1-1/8 ID viton Oring.
Change to 1/16th by 3/8th OD HARD viton Oring clutch push rod seal (after market oring nut item for belt drives)
Oversize 3/32 x 11/16 ID viton O ring shift lever – force into place with a wooden shaft.
Tranny cam & shift pawl - force in oversize 3/4 OD x 3/32 viton Orings
Forcing in the oversize orings takes some patience.

Dano
Don't know what you mean by "metal cap" Just two orings added.

Must be the way the light bounces off them in the pic.