Transmission output shaft seal

[guitardad]

The bike in question is Lion_Lady's 2004 R1150R Edition 80 Rockster, with almost 60k miles. It's been "weeping" a little oil which drips from the boot between swingarm and FD for a while, but the leak is worse over the last month. Looking up inside the swingarm, I can see that there's oil a long way up there. So I'm pretty sure the leak is from the transmission output shaft seal. Last couple of times the bike has been to the shop, we were told the trans output shaft seal would need to be replaced eventually. And with November upon us, if the bike sits for a while it's not such a big deal.

Now my Clymer says to split the transmission case to drive out the old seal from the inside. As does my R1100 factory manual (5-speed, I know, but still!). Has anyone ever replaced the output shaft seal without taking the transmission case apart? How, and how hard was it?

[boxermania]

First of all I have never seen the need to do it on an R, however, I'v done it many times before on other vehicles.

The seal dimensions are 25x40x6 and I assume to be 25 mm on the ID, 40 mm on the OD and 6 mm deep. There are a couple of ways to remove it without spliting the case:

1) Pry it out wih a screwdriver....might hve access problems
2) Fashion two J hooks to sneak past the rubber portion of the seal and pull equally on both sides. Will require a bit of effort.
3) My favorite, drill a small hole on the metal part of the seal and using a sheet metal screw driven into the metal proceed to pull on the seal, visegrips, or better yet a sliding hammer will do the trick.

Good luck and let us know how you made out

[fallingpines]

My FD boot used to leak enough to lightly cover that area, usually no real drips. I was running synthetic gear oil, then switched to non-synth and the leak has gone away completely.

[guitardad]

I like the screw and slide-hammer idea. I'll let you know how that works.

[Lion_Lady]

It has begun... bike is sitting in the garage in a state of partial dis-assembly. Guitardad is going to take the tranny out and do a spline lube as well ("Gryndl" is approaching 60K miles might as well take care of that while its apart).

Will post pics soon.

P

[sweatmark]

Looking forward to the photo documentary! And hoping you'll find perfect splines.

[boxermania]

I don't mean to be the bearer of bad news, however, with 60K mile there will be some wear on the tranny input shaft, but significantly less than the one you'll find on the clutch disc hub.

The question is if the extent of the wear, in the tranny input shaft, falls within the serviceable range, otherwise replacing the clutch disc on a semi worn tranny input shaft will accelerate the second round of wear as the tooth clearance is already excessive.

There have been extensive posts on the subject, as the issue is one of design and materials.

Best of luck.

[guitardad]

Just a quick update.... Yes, there is some wear on the trans input splines. But not too bad, so no trans rebuild to replace the input shaft. (That's out of my league anyway - it'd have to go off to Anton Lardiader for that kind of work!) Clutch measures 6 mm (vs new at 8 mm and wear limit of 4.5 mm) so I figure we'll get 100k out of this clutch. The output shaft seal was definitely leaking, so I'll be working on that replacement this week. And then the reassembly begins!

[Lion_Lady]

Okay... pictures!



Not supposed to be dry like that, is it?


Nope. Not good. Could be worse. No missing bits, just a bit rough.


After cleanup.


And on to replacing the seal, next. Sorry there aren't more "in process" photos. But guitardad has had his bike apart so many times, he just isn't into the photo documentation thing.

One more:


SO sad, isn't it?

P

[guitardad]

To answer my original question: Yes, one can replace the transmission output seal without disassembling the transmission. Here's how I did it....

The suggestion from Don at Bob's BMW was to use some dental picks to pry under the seal, and pull it out. That would avoid any risk of damaging the bearing by drilling into (and thru!) the seal. But every pick I have was too flimsy - it bent WAY before the seal moved. So I ended up drilling a couple of 1/16th holes in the seal, and putting in a couple of wood screws. One was too close to the edge, and just pulled out. I clamped vise-grips on the other, pried a little, and out she came!



With the seal out, I could see the bearing was a sealed one. I wiped up all the oil in there, along with any metal bits from drilling.



Interestingly, the new seal is different from the old one. When LL went to get the part, it wasn't in stock, which is unusual for Bob's BMW. But they were purging their stock of the old part, and making sure we got the new one. New on the left, old on the right.



I used a small PVC pipe fitting as a drift. It was the right size for the job, and the plastic is less likely to damage the seal. It's actually what I bought as a tool to install a swingarm bearing on my airhead - does that mean it's a BMW special tool?



The easy part is tapping the new seal home. Job done!



All in all, not too bad a job. The hardest part was drilling the seal to put the screws in. The hole I thought was centered in the metal part of the seal was actually too close to the inner edge, and tore out. The one I thought was too close to the outer edge was just right. So that was an important lesson.

Bike reassembly is underway!!!

[Lion_Lady]

YAY!!! ITs a motorcycle again! . . . FINALLY got to ride after "Snowmageddon" subsided.

P

[Kobe22]

Wow, you guys are amazing! Can't believe you pulled that off, most folks would be too intimidated to even try! Thank you both for blazing this dark trail! Heck, seems like you might be able to build one of these bikes from scratch! I just love to see folks pick up big challenges and just go! My bike only has 3175 miles on it so I do pray its a very good experience between now and when this 'hack' is necessary... it really is priceless what one can learn here

[Lion_Lady]

Wow, you guys are amazing! Can't believe you pulled that off, most folks would be too intimidated to even try! Thank you both for blazing this dark trail! Heck, seems like you might be able to build one of these bikes from scratch! I just love to see folks pick up big challenges and just go! My bike only has 3175 miles on it so I do pray its a very good experience between now and when this 'hack' is necessary... it really is priceless what one can learn here

Well, Kobe, guitardad has had his bike ('94 R1100RS) completely apart 3 times. When he first purchased it used, he didn't know that the hiccup in shifting from 3rd to 4th was a red flag indicating that the transmission was about to self destruct. He pulled the tranny sent it off to be rebuilt and installed a "loaner" transmission from a fellow BMWBMW club member for the riding season. When the rebuild came back, he did it again. Then he lost the oil sight glass a year ago, while riding in the Cape Fear 1000 rally. Another rebuild.

Our local (to you as well) BMW club is amazing. Lots of folks ready and able to offer assistance and guidance in whatever you may endeavor to do to your bike. Next weekend is our annual BMW Bikers of Metro-Washington Square Route Rally held near Thurmont, MD. Come up for the day on Saturday if not the whole weekend. Great riding, great fellowship. Cool stuff.

P

[Kobe22]

Whilst on the subject of dismantling, I noticed this

T'is got me a little worried, all I did was ride her back from Virginia Beach. I'm guessing Giulio -the original owner- in his enthusiastic attempt to change the bolts may not have torqued it up correctly.

I posted on another oil related forum and got a response. I was going to chug it along until the 6,000 mile service but I really don't know....

Poor baby is bleeding....
Please let me know what you both think...

Thanks a bunch