Final Drive Leak

[blackcat]

I had a small leak from the final drive on the 76 Lemans so I ordered a new seal but it didn’t seal properly.



I removed the seal, cleaned up the edges which really weren’t a problem and discovered a tiny blemish which I filed and added a small amount of epoxy and filed that down when it dried. I installed the new seal and it still leaked so I set the seal a little deeper and no leaks over night. I thought that settled the story but after a ride today it was still spitting some oil. NG. I ordered some Yamabond yesterday and I’m going to order another seal(#3) tomorrow morning and hopefully this combination will solve the problem.



You can’t see it in the photo, but it will show a tiny amount of oil after it sits for awhile and of course it shows up on a ride. Not as bad as above but any is no good.  At 4 o’clock there is a dark spot where there is some residual epoxy and I’m guessing it’s oozing some from there. I thought about smearing it with the yamabond but that seems like a temporary fix at best.

[Tom]

Isn't there an inner seal too? 

[pehayes]

That is NOT a little leak.  What are you planning to do with this Yamabond?  Gluing the seal into position is a big no-no.  Who will take it out next time?  Where was this blemish that you repaired?  How did you get your new seal back out without damaging it?  Did you remove the cover from the box or just pry the seal out from its position?  Gee, those teeth look very nice.  I suspect they have been well lubricated.  Lubricant on the drive teeth comes from the deep/inside seal, not from the big outside one that you photographed.  No indication where you are from so that someone nearby might help.

Patrick Hayes
Fremont CA

[Tom]

Y'ep.  Haven't done one for awhile.  No mention of it so I thought that was replaced.

[Loop Tonti EV]

It's possible that it's the inner seal leaking.

[Tom]

"Lubricant on the drive teeth comes from the deep/inside seal, not from the big outside one that you photographed."   

[blackcat]

That is NOT a little leak.  What are you planning to do with this Yamabond?  Gluing the seal into position is a big no-no.  Who will take it out next time?  Where was this blemish that you repaired?  How did you get your new seal back out without damaging it?  Did you remove the cover from the box or just pry the seal out from its position?  Gee, those teeth look very nice.  I suspect they have been well lubricated.  Lubricant on the drive teeth comes from the deep/inside seal, not from the big outside one that you photographed.  No indication where you are from so that someone nearby might help.

Patrick Hayes
Fremont CA

The top photo is after installing the first seal and I removed it and installed the second seal which also leaked but not that much. That is when I set the seal deeper and it did not leak until ridden and very little leaked. We are talking spittle, not drips as above.

I was going to use the Yamabond on the edges of the seal.

The seal was removed from the outside, cover has not been removed by me.

I have watched the seal seep from the large seal and never noticed any oil trail from the teeth to the large seal.

If the inner seal has to be changed I will send it to Steve in Georgia as he has worked on my CX final drive in the past.

This bike has less that 16,000 miles on the clock.

 

[n3303j]

I routinely install seals by coating the bore and the seal with an extremely light coating of automotive RTV silicone. Put it on and wipe it almost off with a clean finger. The seals slide in without dragging or damaging their exterior. The silicone fills any defects in the bore. A little bit of silicone is wiped off the seal by the bore and remains outside. I wipe this off with with a clean wipe. I let it all sit for 24 hours before reassembly.

Never damaged a seal with RTV silicone installation.
(Dry installations have torn seal OD surface)
(Oiled installations have popped out of location)
Never leaked around a seal.
Never had a seal pop out of position.

Seal still can be removed by normal methods.

[blackcat]

I routinely install seals by coating the bore and the seal with an extremely light coating of automotive RTV silicone. Put it on and wipe it almost off with a clean finger. The seals slide in without dragging or damaging their exterior. The silicone fills any defects in the bore. A little bit of silicone is wiped off the seal by the bore and remains outside. I wipe this off with with a clean wipe. I let it all sit for 24 hours before reassembly.

Never damaged a seal with RTV silicone installation.
(Dry installations have torn seal OD surface)
(Oiled installations have popped out of location)
Never leaked around a seal.
Never had a seal pop out of position.

Seal still can be removed by normal methods.

Thanks, I was going to do basically the same thing but glad you posted your experience.

I have replaced these seals before on my 1000Sand CX without any problems but this bike was sitting around dismantled for some time.

[guzzisteve]

Hey Cat, I would make sure the drive isn't building up pressure. Might be the heat outside causing it to get more pressure. I've drilled the cap on them and swingarms for a vent many times. I wouldn't worry about new inner seal unless you have oil on your axle. Inner seal was also brown like the new outer seal. They seal better than the blue ones.

[Antietam Classic Cycle]

Run until hot and then "burp" it - open and close the fill plug. Works sometimes.

[blackcat]

Hey Cat, I would make sure the drive isn't building up pressure. Might be the heat outside causing it to get more pressure. I've drilled the cap on them and swingarms for a vent many times. I wouldn't worry about new inner seal unless you have oil on your axle. Inner seal was also brown like the new outer seal. They seal better than the blue ones.

"Run until hot and then "burp" it - open and close the fill plug. Works sometimes."

I tried burping the drive but that didn't work and the axle does not have oil on it but that is from memory, I'll pull it out this morning to double check.  In the meantime, I have ordered another seal and will clean up the shoulders again where the seal sits and give it a light coat of the Yamabond as described above.  Currently, it just spits a little bit but that is unacceptable. The funny thing is that I was using this same drive on my CX while Steve was fixing the original final drive on that bike and I had no problems with this drive, but before I went for a ride on the Lemans a few weeks ago I got paranoid about the volume in the rear drive and instead of just draining the oil and checking the volume I squirted in some oil and went for a ride. That is when it started leaking.

Oh well, I'll get it sorted sooner or later. Thanks.

[acogoff]

    The way you have been switching the box around between bikes , I would have a real close look to make sure your leak is not at the pinion.  both O rings need to be replaced each time the box is off.

[blackcat]

    The way you have been switching the box around between bikes , I would have a real close look to make sure your leak is not at the pinion.  both O rings need to be replaced each time the box is off.

You mean the one o-ring where the swing arm and the final drive join, yes it is fine and that isn't where it is leaking. I've made that mistake before and it was one of the first places I looked for oil.

Steve, Other than a film of grease, there is no oil on the axel. Thanks for the tip.

[moto-uno]

  In a drive box that only takes a cup of oil , how much of a squirt did you give it ? It's only a second to remove the level plug and verify .  Peter

[jacksonracingcomau]

The funny thing is that I was using this same drive on my CX while Steve was fixing the original final drive on that bike and I had no problems with this drive, but before I went for a ride on the Lemans a few weeks ago I got paranoid about the volume in the rear drive and instead of just draining the oil and checking the volume I squirted in some oil and went for a ride. That is when it started leaking.

I don’t see the amusement, nor why you did it
At least you know why it leaks, not the first one, seems weekly on here
Why does no-one do it to cars ?

[blackcat]

  In a drive box that only takes a cup of oil , how much of a squirt did you give it ? It's only a second to remove the level plug and verify .  Peter

Only a small amount of oil was squirted in the box and for all I know it has nothing to do with it leaking as it could just be a coincidence.

[blackcat]

I don’t see the amusement, nor why you did it
At least you know why it leaks, not the first one, seems weekly on here
Why does no-one do it to cars ?

It wasn’t meant to be an expression of amusement,  more odd.  Actually, I don’t know why the original seal leaked other than maybe it was just time for it to go.

“Why does no-one do it to cars ?”

If the final drive in my car locked up there is a good chance I won’t be killed, can’t say the same thing on a bike.

[blackcat]

Just to finish this up, upon further investigation the hub was corroded at the one spot on the final drive hub. The few times that I have replaced the large final drive seal I just cleaned up the edges, banged in the new seal and that resolved the issue.  This bike sat apart for years in what I was told were less than ideal circumstances in Miami, so I’m guessing this might be why the hub corroded.



I also replaced the the small inner seal in the process.

[jrt]

That should polish right out

[blackcat]

That should polish right out

That is the polished out version. 

I guess a filler could have been used instead of buying a new hub but given the amount of work to remove and install a new one it didn't seem reasonable to take that chance.

[Frenchfrog]

If the part was out of production or around 500 bucks it would have been worth turning the pitted areas out and making a sleeve but unless you could do that yourself a new part is cheaper...It's really quite surprising how much is still available for the Tontis !

[blackcat]

If the part was out of production or around 500 bucks it would have been worth turning the pitted areas out and making a sleeve but unless you could do that yourself a new part is cheaper...It's really quite surprising how much is still available for the Tontis !

I considered an auto body filler that is meant for high temperature conditions like powder coating, and if it was an easy swap I would have taken that route but I really didn't want to do this twice.

[Ncdan]

That should polish right out

Polish out?? Lol give me the name of your polish😂😂🤣🤣

[guzzisteve]

Tom,      See, it wasn't too bad of a job. Glad you got it sorted.

[blackcat]

Tom,      See, it wasn't too bad of a job. Glad you got it sorted.

Steve, I should have gotten back to you about this but I started down the road and it ended up being easier than I thought. My back up plan was to send it to you if I wasn't sure of my progress.

[guzzisteve]

I knew you could do it, I'm still on Stelvio.  As long as you have the same backlash it's all OK. There was only 1 race to take off, I use a bearing splitter and steering wheel puller plus a bit of warmth.

[blackcat]

I knew you could do it, I'm still on Stelvio.  As long as you have the same backlash it's all OK. There was only 1 race to take off, I use a bearing splitter and steering wheel puller plus a bit of warmth.

Yes, I had a feeling that you might be on the Stelvio for awhile which is the other reason why I decided to give it a go. Like changing the belts on the Daytona, I was apprehensive at first but it wasn't that bad once I got started.

[wirespokes]

I might have tried brazing it up then turning it down.

Glad you finally got to the bottom of it.

[blackcat]

I might have tried brazing it up then turning it down.

Glad you finally got to the bottom of it.

Next time I have to have some machine work done, I'll have a chat with the owner about such a process but I assume it would cost me more than just buying a new one. I hate the idea of tossing it as the splines are in great shape.

Yeah, I am glad that is done though I kept an eye on it for a few days looking for leaks.