Bonneville America Forums Forums Technical Forums General Tech Counter-shaft Sprocket Seal Change Tips

Folks:
I replaced my counter-shaft sprocket seal at 14k back in '06. I managed to bugger up the outside of the seal on the install and now, at 33k, it's leaking again. Well, I'm pretty sure that is the leak. Or my gearbox gasket is leaking, which is unlikely.
There were a few oil drops off the bottom of the bike in the past few months and now it is getting heavier. Not enough to lower my oil level, but it will soon.
I have a spare seal in my box and will install it shortly. It's been a long time and I wondered if there were any tips that would help avoid buggering up the cover of the seal this time around. I seem to remember freezing it makes it easier with a little dielectric grease around it as well.
I learned to break the nut loose before loosening the chain.
Anything else I should be looking to do on this job?

Back when I worked at the Triumph dealer, we had a 675 with the output shaft seal leak. When you tried to drive the seal in, it would roll back the rubber coating on the outside of the seal and then of course it will leak. Is this the problem you are having?
If so, what I did was use a bit of emory cloth (sp?) to smooth off the outside lip of the case and gave it a slight bevel. Then I could drive the seal in without damaging the outside sealing surface.

Bingo. I'll bevel that lip a bit. Of course I don't have the proper drift, but think a suitable size of PVC pipe should work.
Is there any benefit to freeze the seal before the job?

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Back when I worked at the Triumph dealer, we had a 675 with the output shaft seal leak. When you tried to drive the seal in, it would roll back the rubber coating on the outside of the seal and then of course it will leak. Is this the problem you are having?
If so, what I did was use a bit of emory cloth (sp?) to smooth off the outside lip of the case and gave it a slight bevel. Then I could drive the seal in without damaging the outside sealing surface.

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Wouldn't think freezing would be a good option.. while I understand the principal, I don't know how the rubber on the seal would react when smacked into place. I'm thinking warm and flexible more than cold and rigid.
I use a socket to drive seals when I can't use my seal driver but a proper size piece of PVC would probably be even better.

We freeze a lot of bearings at work before we install them but I don't think freezing a seal is a good idea - you probably couldn't get it cold enough to make a difference anyway....
Go with chy's idea of beveling the sharp edge of the bore and use a little lube on the bore and the outside edge of the seal - oil, vaseline, etc.

The real key is to have a good driver that fits the seal properly and having a real steady hand and a good aim. Tappy tap tap...

Al, one of those little Stanley dead blow rubber hammers is really handy for driving seals because it doesn't rebound and spoil the hit.

Great suggestion. I grabbed one yesterday traveling in NY at a Harbor Freight. I had previously used a big rubber mallet, but it did rebound too much. I'll hopefully pop this seal in over the weekend. I read you don't have to loose the chain, just pull the sprocket. I have an 18 tooth, but will try it.

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Al, one of those little Stanley dead blow rubber hammers is really handy for driving seals because it doesn't rebound and spoil the hit.

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Well, I pulled my sprocket cover and the sprocket today. I'm just not sure it's the sprocket seal that is leaking. There was some debris above the seal, in those cavities, but the seal looks great and is completely intact.
Has anyone had to replace that gearbox gasket below the sprocket? I'm thinking it could be that.
The oil is just a light film over the bottom part of the motor. The drips are coming off the oil filter. It doesn't seem to be coming from the oil sending unit, but somewhere above.
I cleaned it up for now and will check again in a few weeks. It is quite easy to pull the countershaft sprocket without loosening the chain. The nut was very loose and was easily removed by hand (after flattening the washer). I torqued it after the new sprockets/chain install last year, but remember having to put some serious grunt into loosening the nut. Any comment on that?

You could ignore it and just used some brake clean every once in a while.

Well the nut shouldn't be loose.. at all...something is amiss.. but that's not going to cause it to leak.

I did a little searching on Rat.net and found most replies on leaks were centering around the counter-shaft sprocket seal, but one guy said his "galley plugs" behind the starter were leaking and the oil was finding it's way down to around the filter. Apparently, you pull the starter to access these plugs, which he pulled out, cleaned, applied locktite pipe dope and reset. Behind my sprocket was a lot cleaner than I remembered it being on the last change, with no oil dripping down over the gearbox cover as seen in this picture.

The galley plugs are behind the starter. You have to remove it to get to them, but this is very easy only two bolts hold it on and they are accessible with a ratchet and extension. The two galley plugs are actually just hex set type screws. just turn them out and clean them, I re installed them to the same depth with a good coating of locktite pipe dope, the kind that sets hard and have had no leaks since from there any way, I am having to replace the output shaft seal now though.

I missed the part about the nut being loose. That definately should not be. That sucker should be tight.

Well, it's torqued to 97 ft-lbs now. We'll see what happens.

I'm not saying this is part of your situation, since you said the area behind your sprocket was relatively clean this time, but that mess on the gear box cover can also be from a build up of chain lube.

It is odd that the sprocket nut would be loose if it was torqued and locked with the washer...?

I will definitely pull the sprocket and take another peek after some more miles. I rode it about 60 miles today and the oil is still lightly collecting under the motor in various spots.

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I'm not saying this is part of your situation, since you said the area behind your sprocket was relatively clean this time, but that mess on the gear box cover can also be from a build up of chain lube.

It is odd that the sprocket nut would be loose if it was torqued and locked with the washer...?

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