i have a leak that looks like its coming from behind the front sprocket, i took it off and there is a little hole that seems to be for oiling the main shaft out of the tranny. i replaced the seal there and it is still leaking. would replacing the sprocket itself help? what is this little pin hole actually for?

 

I do not know about the hole. I have had a leak there. The problem was the way the oil seal is enclosed in the oil seal retainer. I had to press the seal right into the retainer rather than allow the installation of the screws to do that. I also included a little Permatex Ultra Blue with the seal. Problem fixed.

If you have removed the sprocket but not the retainer and seal behind it you may not follow what i have said. If so then remove the sprocket again, the retainer is held on by 3 small Phillips head bolts so remove them, and the retainer and the oil seal will come right off - no prying etc necessary.

Ar least gives you a better look at things, perhaps see better where the oil is coming from.

 

Where abouts is this little hole Looking at the trans sprocket (behind the sprocket on the case ) Not the end of the main shaft ?

 

Where did you put the permatex on the seal Thanks i am going to have to change mine soon

 

Maybe the little hole is a missing screw !!@@##

 

I put the Permatex on the side of the seal that goes into the seal holder. The problem i had was that the seal did not fill the seal holder. With the 3 screws tight the seal was not held in contact on both sides. Perhaps it depends on the manufacturer and i had ones that were not so good.

In case you do not know: Oil seals are directional. I do not recall which way it goes. Pay attention to the way it is installed as you remove it. I expect that the side with the spring should face into the holder but you should confirm this.

 

Hey Blc1313, I know this is an old post Im new to this forum and wanted to ask you if you ever found out where the leak was coming from? I have an 83' as well with the same issue. I can't go for a long ride with out oil getting on my back tire and its been quite frustrating as the bike runs good just feels unsafe with all the oil on my tire.
I soon as I park the bike it leaks almost instantly from under the front sprocket area (no where else surprisingly). I changed the rear main seal, the gasket holding the cover, sprocket and still no luck. Kinda stumped at this point. Any advice would be great!

 

If it's still leaking from behind the sprocket, did you check the main shaft surface before you fitted the new seal? Also check the gearbox breather isn't blocked.

You can get leaks between the main shaft and the sprocket, as the oil works its way out down the splines. Applying Permatex goo to the sprocket splines before fitting it will usually seal it up, or for a more permanent solution buy one of these, it's a capped sprocket nut that will stop the leak

​​​​​​https://bikersnos.com/products/nos-g...t&_ss=e&_v=1.0

 

Appreciate the feedback Phil13! I checked the main shaft surface and all looks to be good. Just purchased the capped sprocket nut. Let's see if that helps with the leakage. Will keep you posted. thanks!

 

Brainfart there, I should have said check the hub of the sprocket where it enters the seal.