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Leaky Shift Shaft Seal........

7K views 18 replies 6 participants last post by  MotoJockey 
#1 ·
I posted this on a different Forum but wanted your opinions as well.
I'll try to make this short, but............

While on our recent 50 day cross-country, I developed a nice little leak out of the Shift Shaft Seal on our 2014 SGS. Had close to 95k on the bike at the time. Not a bad leak and it would wait till we got back. After we got back, I went in to replace the Seal, as well as install a new Dark Horse Man-o-War Motor Sprocket that I've been wanting. (see other thread I started on that). Anyhow, taking the suggestions of multiple people, I decided to use the smallest little wood screws I could find in my shop to remove the old leaky seal. Well, it apparently got crooked while screwing it in and left a nice not so little gouge in the sidewall of the bore in the Tranny Housing that the seal fits into. See pic below......






So what I've done to this point is, on the 1st attempt I lightly sanded the extruding burr off the damaged area, crossed my fingers and put a new seal in. Fail......
Next time I took a little dab of the Permatex Gasket Dressing (Hylomar Blue) that I had, right on the gouge, crossed fingers. Fail.....
Next time, after replacing the Shifter Mechanism Shaft that the seals ID rides on with a new one, (thinking it was worn/grooved/scratched), I took the same sealant, put some extra on the gouge and also lightly all around the the rest of the bore. Fail......
This last time I gooped the sealant all around the bore pretty good, but not too much, installed the seal, let it set up for a few hours, then reassebled everything and let it sit overnight. Better, but still fail.....
This is the sealant I've been using and I'm beginning to think maybe it's not the right stuff.......





So, I'm at the point where I can go back in and try it ONE LAST TIME before I either have to buy a whole new Tranny Case, ($600!), or take mine to the local Machine Shop and have my buddy do a "Bore and Sleeve" to repair what I phucked up. However......... I'm really thinking I can fix this with a different type sealant...... I think this stuff I've been using is too soft. What do you guys suggest as far as what sealant I can/should use to seal this? I REALLY don't want to pull the Tranny out for either repair or replace. There has to be a better sealant that I can use for this that will work, right? I have this other stuff, but I'm not too sure about that either. I'd rather hear from you guys first...........






On a side note, I'm getting really fast at tearing this thing down and putting it back together again, lol!! Plus, I found a great way to remove the seal without drills and screws. Just take the Tranny Cover off and push the Shifter Mechanism back into the Tranny and it gets the Shift Shaft out of the way so you can pop the seal right out! (see the top pic again) I love YouTube!!
 
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#6 ·
Possibly, but if there is a better sealant that I can use, I'd lean that way so as to not make this issue worse by boogering up the bore surface even more than I already have.
 
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#7 ·
I'm thinking the bore. The Shifter Shaft, attached to the Shifter Mechanism, is brand new, as are the 4 seals I've installed. But by the time it leaks, I tear it all down, and pull the washer off to expose the seal, the whole seal area is wet. Very hard to pinpoint the exact location at that point.
 
#4 ·
I don't understand why the Permatex isn't working, I use that same stuff quite often. There's no oil pressure inside the trans so any leakage from the seals is from gravity and cling. Check to verify the vent hose isn't plugged, just pull it off the fitting and blow thru it.
 
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#8 ·
Double checked the vent hose and it's as clear is it gets. Blew through it when I had the top Tranny Cover off. I thought this sealant would have been good to go as well! I wonder if I need to let it set up more before, and after, I install the seal? That black stuff I have in the last picture is from sealing the molded plug that is pushed into the Crankcase for the Stator wires going to the Voltage Regulator on my 03 RK. That stuff worked great! (I'll do a proper repair whenever I get into it that far.)
 
#5 ·
take mine to the local Machine Shop and have my buddy do a "Bore and Sleeve" to repair what I phucked up.
The machinist in me says: This was my first thought. Then looking closely, it can be tig welded then, clean up the bore.

In my world, making a bushing would be the easier way, (if the case wall is thick enough) but either way, the case would need to go on a mill. As there's really no other way to get a true inline bore alignment with the hole.

The wall thickness is so thin, a bushing would be super thin and prone to cracking. I would shoot for the tig / machine fix.
 
#9 ·
Yeah, if I need to pull the Tranny out for repair, it'll need to be so inexpensive that I don't just start over with a brand new Tranny Housing that comes preloaded with all of these goodies listed that I still need to cross reference this morning, but it DOES include the Shifter Mechanism Shaft Sleeve and the Shifter Shaft Seal already installed!

TRANSMISSION CASE SUBASSEMBLY W/ 3594, 8963, 8967, 9701, 11161, 12074, 16574-99A, 35082-07, 35122-06,
35186-06, 35241-06, 35242-06, 40659-06, 66290-06 & 11000101 (BLACK)

The more I think about it, the more I lean this way........
 
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#12 ·
Getting way to complicated now, overthinking ! That seal was leaking beforehand. I don't think that screw damage has anything to do with this seal still leaking. I've removed those shift shaft seals the same way and have left some screw thread marks in the same area, but the new seal cured the leaks without adding sealer or anything.

So what else can be causing the leak at the shift shaft seal ? I suggested the trans is getting internal pressure from somewhere, the most common is the vent hose getting plugged by hole spiders. Not funny, seen it plenty over the years ! Now that's been ruled out. Actually if the vent is plugged all the left side seals will leak not just the shift shaft seal.

So what's left ? 6spd trans with how many miles, 95k plus ? How many cycles has that shifter been thru in 95k+ miles, good question ? Trans case worn out where bearings and bushings aren't incorporated ? Air cooled engines usually get serviced between 35 - 50k miles, but transmissions go forever until they break !

Just some things that I'm throwing out there for conversation. Transmissions do wear out too ! The bore might be worn such that the shift shaft wobbles to much for the seal to work. I would mic the shift shaft and the bore to see if there's excessive clearance.

One other little diddy I can throw into this conversation. Is there enough room to install double seals or a single double lip seal ?

Long post, sorry !
 
#13 ·
Liking the possibility of the double seal theory there @SCHMIDTY !! I'll have to measure the depth of the bore when I tear it down again. I think I need a day away from it right now, lol. o_O
The only thing that is not brand new is that damn illusive Shifter Shaft Sleeve!! PN- 35186-06A..... There doesn't feel like there's a lot of slop in it at all, which is why I didn't feel bad about reusing it instead of waiting for it to come back in stock in DECEMBER!! If I have my guy machine one of those too, I may as well get the Tranny Housing from MoCo with all that in it already.
 
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#14 ·
You could try some liquid metal repair, usually 2 part compound mixed together, once set can be machined, filed, drilled and taped. In the UK there's a product called Devcon 62345 plastic steel apoxy. If you use enough just fill the damaged area you should be able to smooth it back with grit paper. I've used this product many times during my engineering career. Give it a go you've nothing to loose.
 
#15 ·
So I wrote up a little spreadsheet on a PDF file showing the cost difference and savings of buying a complete Tranny Housing Subassembly vs cost of each individual part cost. Depending on my buddys price, I'll probably just get the new Tranny Housing. I'll have to buy a bunch of this stuff anyhow to put it all back together correctly as it is, sooooo........

Plus, it'll take care of that little mishap that occured while drilling out that broken bolt a couple of weeks ago, lol....
 

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#16 · (Edited)
So, @SCHMIDTY , the double seal theory is out. The, bore isn't deep enough, damn it! Good thought though!
Upon pulling this last one out, the one with the little bit extra sealant, I noticed the sealant seems to have become sticky gooey, almost gummy, but definitely not set up like I would have thought and wanted to see. Did it have some sort of reaction with the Assembly Lube I used? The grease the that MoCo put on the seal? The Bel-Ray tranny fluid? I don't know, but it's too snotty for my liking.

Automotive tire Rim Automotive wheel system Gas Wood

Eye Automotive tire Fluid Gas Liquid





With this in mind, I'm thinking clean the dog crap out of everything with brake cleaner and alcohol, leave the assembly lube, or tranny fluid, only on the ID of the seal and shaft, put a goodly amount of some regular high temp RTV in the bore, and instead of sinking the seal to the spec'd out depth of 0.120" - 0.140", I bury it up against the back of the bore. This will keep the seal lip still riding on the fresh surface of the new shaft. I've seen videos of guys setting the seal all the way back into the bore, and thinking it prolly won't hurt AND maybe help it to seal on a seperate surface. The sleeve is deep enough into the housing that it won't come in contact with the seal either. I'm really getting driven to fix this damn thing instead of pulling the whole tranny out for repair or replace, lol, but I'm starting to run low on options here.....
 
#17 ·
Update- I pulled into the shop earlier this afternoon after it's 3rd test ride in 3 days for a total of about 300 miles, and everything is bone dry! Although I feel good about the repair this time, you can bet I'll be keeping an eye on it for quite a while though, lol.

On a side note, I was able to hook up with my machinist buddy on Monday to discuss all this.........
1)- He said he THINKS he may have one of those illusive Shifter Shaft Sleeves in a box somewhere, but if not, a piece of cake to make a new one...... or two.
2)- He has some special two-part epoxy that he would use on the gouge I made, if we have to get back into it. He said he'd come by my shop and mix it, lay it in the gouge, roll it into the gouge with a wet socket, and lightly sand it down. Again, a piece of cake......... for him! (This option was mention here earlier, but I was gun shy to attempt it myself for fear of jacking the bore in the Housing up!).
3)- Worse case scenario, I have to pull the Housing, bring it to his shop and he would plunge bore it, sleeve it, weld the sleeve edge to the housing, and grind it flush. All for like $80 - $100..... Which is better than tracking down a Tranny Housing that seems to be as illusive as that damn Sleeve!!

Either way, at this point, I'm back up and riding! Now to move on to the next project. Just not sure if it's one on the bike, or one for the wife because I've fallen pretty far behind in that category, lol!
 
#18 ·
It sounds like you've fixed it, as I mentioned earlier I was pretty sure filling in the gouged area would do the trick. I've fitted 100s of oil seals in my working life and if ever the outside of where the seal fits is damaged I've always experienced leakage, it doesn't matter how good the seal fits round the shaft oil will always find a way out through a damaged area. So providing the product you used is suitable for repairing damaged metals you should be good to go.
 
#19 ·
Update, and hope I don't jinx myself..........

1000 miles on the last repair using the Permatex Black Optimum Max Flex and all is well! At least I know I have a machinist buddy in my corner if it fails again to fix it permanently next shot. Learned a couple of good lessons here on this little misadventure, for sure! Thanks for all the suggestions!
 
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