K1100 Final Drive Seals

[DJW]

In addition to the u-joint issue (see other thread), my final drive has been puking oil . There is glop all over the face (toward the wheel), and when I pulled the boot from between the final drive and the arm, oil came out. So, it would appear that both oil seals, well, aren't.

Is there another explanation besides this most obvious one? If not, does replacing these seals come short of a complete rebuild of the final drive, as far as complexity goes. Also, according to Max's fiche, the seal leading toward the drive shaft is not available. What are my options?

Thanks.

 

[CustomSarge]

Uhoh....

Hi Don; it sucks but, unfortunately I think your suspicions are spot on. Seal failure is most often the warning of bearings gone south. Anybody got another opinion?
I'm not up on rebuild $, but a servicable used one is something I'd look into. At least until the rebuild is done. I wonder how different an oilhead final is... and which years may be valid.
I'd be surprised that, between the bearing & power shops in Kzoo, you can't get the driveshaft seal. Good Hunting... <<<)))

 

[PGlaves]

The large seal, the large crownwheel ball bearing, and the O ring are easy to replace. A heat gun and basic hand tools are all that is required usually. However, the pinion bearing and seal are another story. Big torque values and several special tools are required. And then everything has to be carefully re-shimmed.

I would take it off and take it to a dealership or other experienced shop with the special tools. Or, I'd find a used one. Low mileage - good splines.

 

[DJW]

Thanks, Kevin and Paul.

Tell me if this makes sense: My rear universal is clearly bad in one direction. Is it this off-balance rotation of the drive shaft that likely damaged the pinion bearing, or at least the seal? Does this explain in any way the failure of the oil seal for the crownwheel?

Any recommendations on a source to rebuild the final drive? How "specialized" is this type of service?

 

[Polarbear]

You can find your seals;

At a good supply (bearing/seal) house in larger cities. Some research is usaully not far from reach, as here. Its probably not hard to find the front seal at such a place, if you cannot find it from BMW. I can't imagine BMW not having it somewhere, though. I'm sure it must be available. I have considerable gear set background, after doing such work exclusively on sets and tranny's. They are not hard to work on with tools, as Paul said about tools! The right ones! BMW actually sells them(tools), if needed. The main issue is when taking it all apart, especially the ring gear/bearing and pinion/bearing assemblies, you keep the exact shims in place as they came out. New bearings? Miles? Inspection? Maybe not, but reshiming may well be required for these. The shiming process is for matching the gear set for proper bite(pinion to ring gear). The new bearings "may" not affect this and the shims in place already are most likely fine. Changing gear sets is where the shims are most likely to need redone. This is a professional job, if you're not mechanically inclined to a fairly high level. If you have this, even not doing these, you won't find the tech too difficult, with some helpful tips here. At the very least, you can take the differential from bike and take it to BMW shop for work. Save some here! My KLT had "warrantee" rear end failure and the price tag was 800$ for rebuild at dealer and this included bearings, seals(same gear set). FYI. Your seals alone won't ding you to this degree. Good luck, Randy13233

 

[cjack]

In addition to the u-joint issue (see other thread), my final drive has been puking oil . There is glop all over the face (toward the wheel), and when I pulled the boot from between the final drive and the arm, oil came out. So, it would appear that both oil seals, well, aren't.

Is there another explanation besides this most obvious one? If not, does replacing these seals come short of a complete rebuild of the final drive, as far as complexity goes. Also, according to Max's fiche, the seal leading toward the drive shaft is not available. What are my options?

Thanks.

A new 2.91 drive is in stock (in black) at BMWNA and retails for $994...just in case you want to ride instead of fix.

 

[DJW]

At a good supply (bearing/seal) house in larger cities. Some research is usaully not far from reach, as here. Its probably not hard to find the front seal at such a place, if you cannot find it from BMW. I can't imagine BMW not having it somewhere, though. I'm sure it must be available.

You would think so, but the fiche says no. I'll be checking with my dealer, but it will be moot if I can't do the work.

I have considerable gear set background, after doing such work exclusively on sets and tranny's. They are not hard to work on with tools, as Paul said about tools! The right ones! BMW actually sells them(tools), if needed. The main issue is when taking it all apart, especially the ring gear/bearing and pinion/bearing assemblies, you keep the exact shims in place as they came out. New bearings? Miles? Inspection? Maybe not, but reshiming may well be required for these. The shiming process is for matching the gear set for proper bite(pinion to ring gear). The new bearings "may" not affect this and the shims in place already are most likely fine. Changing gear sets is where the shims are most likely to need redone. This is a professional job, if you're not mechanically inclined to a fairly high level. If you have this, even not doing these, you won't find the tech too difficult, with some helpful tips here.

I'm fairly mechanical, just not trained or experienced in this type of work, nor do I have the specialty tools (yet). I will probably send it out, if I can get a good endorsement for a shop, and the price makes sense.

At the very least, you can take the differential from bike and take it to BMW shop for work. Save some here! My KLT had "warrantee" rear end failure and the price tag was 800$ for rebuild at dealer and this included bearings, seals(same gear set). FYI. Your seals alone won't ding you to this degree. Good luck, Randy13233

If a rebuild were going to cost $800, I'd buy a new one for $920, although in reality I will instead wait for a used unit. Fortunately, I have the luxury of another bike to ride, so I'm not desperate to get this fixed RIGHT NOW.

PB, thanks, you've given me some things to chew on.

Don

 

[DJW]

A new 2.91 drive is in stock (in black) at BMWNA and retails for $994...just in case you want to ride instead of fix.

Jack,
Thanks, but I can afford to be patient. Besides, my final drive is silver
Don

 

[DJW]

At a good supply (bearing/seal) house in larger cities. Some research is usaully not far from reach, as here. Its probably not hard to find the front seal at such a place, if you cannot find it from BMW. I can't imagine BMW not having it somewhere, though. I'm sure it must be available.

Just a follow-up on this seal. The original part is NLA(superceded), but if you plug the part number into Max's or A&S parts finder, it provides the part number for the replacement part.

One more excuse taken away.

 

[roy]

Final Drive rebuilders

Don, Brunos machine shop in Canada rebuilds final drives. Not sure on costs or turn around time. I believe Brunos advertises in the MOA magazine.

The large output seal next to the rear tire can be changed without diassembling the drive. It takes a little time and care but is completely doable.

 

[DJW]

Don, Brunos machine shop in Canada rebuilds final drives.

Thanks. I have a message into Bruno's now.

The large output seal next to the rear tire can be changed without diassembling the drive. It takes a little time and care but is completely doable.

Yes, looking at the unit, and Clymer's, it looks doable. Unfortunately, I also need a new front seal, which is a whole 'nother deal. Cost will tell.

Don

 

[roy]

Brunos

Don, if I remember correctly Brunos may have some rebuilt drives in stock. I think they occasionally have a final drive, tranny etc. that they have rebuilt and is now for sale. May want to check with them when they call. I would suspect they would mention this as an option if they had one available.

Good luck.

 

[DJW]

... it looks doable. Unfortunately, I also need a new front seal, which is a whole 'nother deal. Cost will tell.

Finally called my local dealer(duh). First quoted me 3 hours to replace the seals, then dropped it to one when I told him I already had the drive off the bike. Dropped it off yesterday. If all goes well, with parts, that should be about a hundred dollars. I can live with that.