Transmission shaft oil leak (NOT rubber shaft seal)

[restforyoursouls]

Hey guys, Did a search. Didn't come up with exactly what I was looking for.

Bike: '73 tx650


I have a leak around the transmission shaft. From what I can tell, the oil is coming out between the shaft itself and the inside surface of the steel spacer that sits around the shaft. The trans shaft seal rides on this steel spacer and the leak is NOT coming out between the rubber seal and this steel spacer.

It leaks at idle in neutral and when in gear as well. Oil level is full but not overfull.

I'm not exactly sure what the fix is for this leak? Please help. I'm trying to get the bike ready to ride to a vintage show this sunday with some friends. Thanks!

 

[XSLeo]

Your front sprocket nut is loose. Torque to spec. 13 Kg-m or 94 ft/lbs
The nut pushes the sprocket against the sleeve, the sleeve against the inner race of the output shaft bearing. If the nut is loose oil can get out by flowing between the bearing race and sleeve, along the inside of the sleeve and out between the sleeve and sprocket.
Many have found this nut barely finger tight.
Leo

 

[restforyoursouls]

You were correct! Used a torque wrench on it yesterday. Went for the first ride tonite after swapping another motor into the bike and no oil leaks that I can see yet. I'll keep my eye on it. Thanks Leo!

 

[xjwmx]

Your front sprocket nut is loose. Torque to spec. 13 Kg-m or 94 ft/lbs

If 94 ft-lbs is right for a '73, the factory manual says only 47 ft-lbs or 36 ft-lbs for others, depending on year.

 

[5twins]

Yes, but if you use those lower values, it will leak. I don't know why Yamaha changed that spec so often, same thing with valve clearances.