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Gearbox Leak - 4 speed, RH shift

Posted: Mon Jul 05, 2021 7:37 pm
by Pict
Oil is getting in to the outer cover, then having gotten that far is obviously just dripping out. I can only guess along the kickstart shaft as it doesn’t leak sitting on the side stand. Suspecting a worn o-ring I’ve pulled it apart for a look and unfortunately there is scoring in the gearbox cover itself where the shaft passes through so oil will always get past the o-ring via the scores. I guess that I’m just getting this now as I did the sealed bearing conversion and am using only oil in the gear box. The grease/oil mix couldn’t have been so prone to finding a way out.

Has anyone had success with sleeveing the gearbox cover to create a fresh sealing surface?
Or give the scores a skiff of JB Weld or similar? Might be tricky to dress it back.
Or go back to grease in the gearbox!

Re: Gearbox Leak - 4 speed, RH shift

Posted: Tue Jul 06, 2021 11:46 am
by vince
Hi, try filling the scores with a gasket goo or heavy grease. Vince.

Re: Gearbox Leak - 4 speed, RH shift

Posted: Tue Jul 06, 2021 12:13 pm
by PeteF
No problem putting in a sleeve (and even a seal) IF you have the equipment.
A lathe and mill would be necessary I think, or you just might manage with a lathe and a pillar drill.
I don't think daubing something in the scores would last long.

Re: Gearbox Leak - 4 speed, RH shift

Posted: Tue Jul 06, 2021 1:48 pm
by Beezabryan
My old heap of **** has been seeping gearbox oil into the outer cover for years.
Just sealed the joint with silicone snot and once in a while I will open it up to clear out the weepings.

Re: Gearbox Leak - 4 speed, RH shift

Posted: Tue Jul 06, 2021 2:37 pm
by Rushour
There should be no oil or grease in the outer cover at all, never had much luck trying to run these on oil - drain the oil out and try it on grease - probably find it will be ok.

Re: Gearbox Leak - 4 speed, RH shift

Posted: Tue Jul 06, 2021 3:48 pm
by Beezabryan
Quite right Rushour but beggared if I will spend valuable riding time doing a proper job when a bodge will do just as well.
Maybe have a look if the K/s pawl quits, last time was 1998 so it may be a while!

Re: Gearbox Leak - 4 speed, RH shift

Posted: Mon Jul 19, 2021 8:00 am
by Pict
Grease it is then! And sealant on the outer cover. And save up for a 5 speed gearbox :-)
Thanks for all replies.