My wife and I are currently on a RTW rour on our 1150GSA.
We are riding two-up. The rear wheel bearing has broken 5 times on this journey. Bike has done 130,000km. I've met many people who had the same problem with their GS when they load it heavy. I've tried a different make of bearing (NSK), but it still only lasted less than 10,000km. I came to the conclusion that BMW inserted a standard deep groove ball bearing (6917) that is not designed to take any thrust, or sideways load. If you load the bike as heavy as we do, the bearing take a lot of thrust and therefore they do not last.

I am changing the bearing now with a Angular Contact bearing (7917), instead of the standard deep groove ball bearing. The Angular Contact bearing is designed to take both vertical load as well as thrust. Old Mini Coopers (1970's) had this type of bearing as wheel bearings.

If you are interested in this modification and the result thereof, I will keep you GS guys posted on the progress. We are leaving the USA soon and will spend the next year in Central and South America, hopefully with no more wheel bearing break downs!

If anyone had done this before, please let us know what the result was?

Johan

Got an internet access and try to respond shortly: you probably have a wrong shimming (bearing will be under axial load (too much shimming)/OR/a freeplay(too little shimming) when you close the bevel box with bolts after replacing the main crownwheel bearing.

With plain wrong shimming they can give up every 5000km or even less(!), people often put the bevel box together with wrong spacing for the bearing (shimming), even BMW dealers can do it wrong, depends how "wrong" you put it and it'll last accordingly. With the correct shimming they go past 100,000+km. I've even seen even over 300,000km per one bearing. Depends how much offroad/load, etc abuse you'll give it.

Another very rare issue can be that particular short and thick shaft that holds the crownwheel bearing at the one end and the smaller bearing in the other end can have its own radial (NOT axial like on the shimming issue) freeplay (and also can kill the crownwheel bearing accordingly in time). The reason may be it's glued together by two details (I may stand corrected here) and the glue can crack. Then you whether buy a complete new bevel box or even cheaper and even better - CNC yourself a new detail (search in ADV rider, one guy did this and improved it) - but this radial play apparently is extremely rare case. Some 99+% cases probably is the wrong shimming issue on "short lived" crownwheel bearigs.

My 10 years old R1100GS is now at 86,000km and counting currently in Brazil and not a single issue on my bike yet while most of the miles I've done two up with my wife + full gear on the bike. I do always carry spare bearing+various shims+main seal with me on my travels, but if I ever need to replace the bearing, I'd rather have a very good measurement tools to get the shimming right than put it on wrong and have it broken again after short mileage.

Ride safe and maybe see you on the road, Margus

The question remains, how do you know when the shimming is 100%. Like you said, even the dealers get this wrong, like they've done with mine.
If you feel play on the wheel, ad a shim, if the wheel feel tight, remove a shim? I no not see any other way of telling when the shimming is 100% or not.
Anyway, I'm installing the Angular Contact bearing tomorrow (myself). The Angular Contact Bearing should be more foregiving if you do not get the shimming 100%.

Johan

Johan, keep us posted on your results! It will be very interesting to many I'm sure. For those who DO need to replace it, if there is a better / stronger bearing, why not?

I suspect Margus is right, so be very careful you get the shimming right. I have no idea how it's done on your bike, so no advice, but I'd start by reading the manual and being sure I fully understand it - and have a stack of shims not too far away.

Changing to another type of bearing is going to guarantee you will need to adjust the shimming. SOMETIMES when just changing to a new identical bearing they measure the same - they should be identical in theory - and no need to reshim. Sadly, BMW doesn't have the best reputation for getting the shimming right from the factory for a number of things, such as airhead gearboxes.

__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com

A (long-winded) video of a FD rebuild including shimming.

http://www.bmwlt.com/uploads/lt_final_drive_rebuild.wmv

(shimming at 34 minutes!)

The new Angular Contact Bearing bearing is doing great at the moment, did 10,000km without problems, as smooth as when the bike was new. . . . . .
I drained the oil and it is 100% clean. In the past (with the standard bearings) there would have been metal shavings in the oil. . . . .

Like I said before, we had to replace the rear wheel bearing 5 times. It was done by a BMW dealer twice, and three times by myself. It is caused by the fact that we overload the bike beyond what it is designed to take.. This is known to be a common problem with the 1150GS as well as the 1200LT (In USA). BMW supplies it[FONT='Arial Unicode MS','sans-serif']’[/FONT]s customers a FAG 6917 bearing which has 19 balls in the bearing. I[FONT='Arial Unicode MS','sans-serif']’[/FONT]ve even tried to use a NSK 6917 which has 17 balls in the bearing, because some BMW dealers in the USA are changing over to the 17 ball bearing as an so called improvement to the original FAG. This did not prove to be successful, as it went out on less than 15,000km, just like the others. Then I decided to do the modification and inserted a Precision Angular Contact Bearing in place of the Deep Groove Ball bearing. An Angular Contact Bearing does the same job as a Taper Roller Bearing, and it makes more sense to me to have two taper roller bearings facing each other, or in this case a taper roller and an angular contact. Mini fans will know that the old Minis have this type of bearing for wheel bearings. The original BMW design only has a taper roller bearing as well as a crown and pinion gear combination facing and forcing thrust load onto the inner ring of the standard deep groove ball bearing that is not designed to handle any thrust load. Not sure why they done this. The Angular Contact Bearing however is designed to take thrust load. The Angular Contact Bearing that I used has the same dimensions as the standard 6917, and sells by the number 7917. Normally the come in a set of two, and I paid $750 for the two from a company in San Fransisco, USA. They also come in difference angels, 15 deg, 25 deg etc. I only got hold of the 15 deg, but would suggest you get the 25deg if you can, as it will allow for more thrust pressure. The procedure to insert this bearing is exactly the same as with the standard bearing. You just need to make sure you insert it the correct way, as it is a taper bearing. I drilled three little holes (3.2mm) in the Ally casing to knock out the outer ring of the bearing. Note that the bearing will come apart like a taper roller, especially when it is worn-out a bit, and without these holes you will not be able to get it out. I hope this information is good enough for you guys. When I have time, I will put a video on youtube how I have done it, as I filmed most of the steps to share with other GS owners. Also note that almost no BMW dealer will do this for you, as it will then be agreeing that there is a problem, something they would never do!
Have done well over 20,000km now, still perfect.

50,000km now after I changed the bearing to an Angular Contact and no problems at all. Below picture might explain it a bit better.



See the difference in the two bearings, above is the deep groove bearing that BMW installed and below is the Angular contact bearing I inserted.


If you do insert an Angular contact bearing, make sure you drill three little (3.2mm) holes like below in order to be able to use a 3mm pin punch to knock the outer ring of the Angular bearing out of the casing, as the bearing can easily come apart like a taper roller bearing and then you cant get the ring out. I used sylicone sealer to plug the little holes and has lasted the 50,000kms with no oil leaks.


Below is the package the Angular bearing came in with with all the relevant numbers you might need to order one.


So it worked for my GS, She has now done close to 180,000kms in total and I hope never to see my sump plug look like below again when I drain the oil of the dif. . . . . . I'm ready for the next 180,000kms!


Hope this helped a bit.

Johan

Can you give an update? How would I know the correct angle bearing to obtain? Any problems of late?

thanks,

james

Hi JC,
Any chance to see your video , I am working on my bike for our RTW and I like the idea of the bearing work .The previous video seems to do not work.

The second photo up from your post shows a picture of the box the bearing came in with the reference number on it.

The caption to the picture reads-
"Below is the package the Angular bearing came in with with all the relevant numbers you might need to order one."

The video doesn't appear to work any more

These might help-

Final Drive Death - Page 2 - ADVrider

Shade Tree Mechanic's Guide to Final Drive Bearing Replacement - ADVrider

http://advwisdom.hogranch.com/Wisdom/ORDBBR%201.0.pdf

you just confirmed why I like this site , great info with great people

The video is found on YouTube. Try searching LT final drive rebuild
In YouTube or use the term bevel box.
I found it.

Hi Johan,

I would like to take RTW trip on my 1150 GS two up. I am interested in rear beaing modification (use different bearing). Could you send me please more informations (photos, etc.) in this case?

Thanks a lot

Fanda

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