My 1977 Sportster has been in storage for 27 years and have just recently got it running. I've noticed a small oil leak coming from behind the drive chain sprocket cover. Is it possible to replace the seal on the sprocket shaft without having to go into the transmission ?
I'm only guessing that the oil is coming from this seal without actually removing the cover, it could be coming from somewhere else.
Any suggestion ?

 

Not real familiar with a 77 but think the seal can be replaced without disturbing the Tranny..

 

Easy job. There is a "seal retainer" holding the seal in place. The retainer is held on by 3 phillips head screws. It is not one of those seals that you have to pry out.

I did have a problem replacing mine - it kept leaking even with the new seals. It turned out that i had to carefully press the seal into the retainer. I had thought this would happen as a result of tightening the screws. Perhaps the retainer was a little out of shape. It would be interesting to hear other experiences of this.

 

Thanks for the reply, I'll let you know how it goes when I get the chance to change it.

 

If it is like the 1971 Sportster I owned long ago, it is easy. Just be sure to use a type of sealant on the retainer that will allow it to shift a little and don't tighten the screws down until you push your sprocket in place to get the seal concentric with the tranny shaft. Then just pull off the sprocket and tighten it in place.
I hope it goes well for you.

 

Good point. This is one of those situations where it is good to have the factory manual as this process is detailed there.

 

I don't know a thing about the 77 ironhead but did it come with that God-awful automatic chain oiler? The oiler on my 75 is located right where you are talking about. Maybe the oil leak is coming from there. Just a wild guess. If that is where the leak is coming from it's about a 5 second fix. I screwed the adjustment on mine down tight and now lube the chain with lithium grease.

 

Also there might be a vent there that might not have a trap on it which I mean that the vent goes up then circles down from the tranny.

 

I'm going to check that transmission vent tube today.
Thanks.