Author Topic: Gearbox Oil Seal  (Read 445 times)

Online bikerbob

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Gearbox Oil Seal
« on: 17.12. 2015 08:31 »
In the previous topic I mentioned the modified bearing for the six spring clutch, but I did not dismantle the primary side just to check on that bearing but to check the rear gearbox oil seal which was leaking. I had fitted a new seal last year when I overhauled the gearbox but was still getting a few drops of oil on the garage floor. On inspection I found that the oil was not leaking from the seal around the mainshaft but from the outside of the seal around the large circlip. I did think of buying a newseal but the same thing could happen again so I decided on a different solution, I removed the seal and smeared a tiny amount of gasket sealant around the outer edge of the seal making sure that none could get into the rear bearing then replaced the seal with circlip and sealed the outside  with silicone sealer. Hope this works time will tell
56 A7 s/a
63 A65

Online coater87

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Re: Gearbox Oil Seal
« Reply #1 on: 17.12. 2015 12:17 »
 I have done this through the years on everything from PTO output shafts, to cheap weed wackers. It seems most of the time the brass ring on the oil seal gets distorted while pushing/pounding in. If there was any scoring in the bore at all, including minor scratching, its going to leak there.

 I am not a fan of silicone, but as long as you are very careful with it, it should be fine. Next step for me would be to change the bearing to a sealed type, use capillary thread locker carefully around the outter rim of the bearing (to help that edge seal), then a smear of three bond and a new oil seal.

 If that does not seal, I believe Harley makes a cookie sheet just for this. ;)
Central Wisconsin in the U.S.

Offline chaterlea25

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Re: Gearbox Oil Seal
« Reply #2 on: 17.12. 2015 20:25 »
Hi ALl,
I posted a topic on this subject  a while ago

Oil can also leak out between the mainshaft and sleeve gear bush, A nut with seal from SRM effects a cure or get turning *ex*
If the nut is even a tiny bit loose oil will also leak out between the sprocket and sleevegear

1961 Super Rocket
1963 RGS (ongoing)