Quote from FlyingMonkeys on December 4, 2023, 11:03 amScott @sheath, you are opening one of the ugliest cans o' worms in the motorcycle world, when you start talking about BMW rear diff bearing failures.
For a long time, BMW refused to acknowledge they even had a rear diff bearing failure issue. Yet....1000's of BMW riders were experiencing rear diff bearing failures, to the point that (and this is serious) riders that were participating in THEE IronButt rally, the 11,000 miles in 11 days Rally would literally carry a secondary rear diff with them on their 2 wheeled motorcycles, so that WHEN...not if, but WHEN the rear diff bearing failed on their BMW's, they had a spare rear diff to install...during that 11 day rally. There were instances of riders having a rear diff fail on them five (5) miles short of the Start of the rally, and that knocked them out of the rally.
BMW lost a lot of customers over that issue, and only AFTER close to 10 years of customers screaming at BMW that it was a design error, a problem related to the BMW bikes, and not the fault of the riders, and AFTER BMW saw the evidence in sales numbers, with many riders going to Honda, because 99.99% of Honda shaft drive rear diffs do NOT fail, as in ever.....finally BMW acknowledged and admitted that they had a problem.
Uh............Good Luck. At least you have the Screaming Yellow Zonker thing going for ya'
Old Yeller! It's not just for Labrador Retrievers anymore! 😉
Thanks for the feedback!
Your input mirrors what I've been reading for sure. At the same time there has been quite a bit written about these units being improperly assembled during the initial build. A bit surprising as this is pretty simple, and BMW would have some pretty exacting jigs. But definitely possible. Certainly the design could have been enhanced (as they did on the newer models). It's almost as if, BMW didn't realize the use case scenario of the newer bikes. To be clear the use of an Angular Contact bearing is a work around, not a design enhancement. But it certainly would increase longevity when setup correctly.
I'm not convinced that improper factory assembly is the issue for the failure of this specific unit. That is what has me asking the question. If we've got rigs out there with 40,000 miles use on and off road without failure, then just doing a correctly setup rebuild with high quality parts would be fine. I don't mind doing a thorough job once.
Hold my keyboard and watch this! 🙃
I don't have an answer to your question, but this might be a good time to post this --->
And if you have a few hundred hours to kill, this Ride Report ---->
https://www.advrider.com/f/threads/sauerkraut-tofuwurst-vegan-bikers-trotting-the-globe.884685/
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Quote from sheath on December 4, 2023, 11:27 amQuote from FlyingMonkeys on December 4, 2023, 11:03 amScott @sheath, you are opening one of the ugliest cans o' worms in the motorcycle world, when you start talking about BMW rear diff bearing failures.
For a long time, BMW refused to acknowledge they even had a rear diff bearing failure issue. Yet....1000's of BMW riders were experiencing rear diff bearing failures, to the point that (and this is serious) riders that were participating in THEE IronButt rally, the 11,000 miles in 11 days Rally would literally carry a secondary rear diff with them on their 2 wheeled motorcycles, so that WHEN...not if, but WHEN the rear diff bearing failed on their BMW's, they had a spare rear diff to install...during that 11 day rally. There were instances of riders having a rear diff fail on them five (5) miles short of the Start of the rally, and that knocked them out of the rally.
BMW lost a lot of customers over that issue, and only AFTER close to 10 years of customers screaming at BMW that it was a design error, a problem related to the BMW bikes, and not the fault of the riders, and AFTER BMW saw the evidence in sales numbers, with many riders going to Honda, because 99.99% of Honda shaft drive rear diffs do NOT fail, as in ever.....finally BMW acknowledged and admitted that they had a problem.
Uh............Good Luck. At least you have the Screaming Yellow Zonker thing going for ya'
Old Yeller! It's not just for Labrador Retrievers anymore! 😉
Thanks for the feedback!
Your input mirrors what I've been reading for sure. At the same time there has been quite a bit written about these units being improperly assembled during the initial build. A bit surprising as this is pretty simple, and BMW would have some pretty exacting jigs. But definitely possible. Certainly the design could have been enhanced (as they did on the newer models). It's almost as if, BMW didn't realize the use case scenario of the newer bikes. To be clear the use of an Angular Contact bearing is a work around, not a design enhancement. But it certainly would increase longevity when setup correctly.
I'm not convinced that improper factory assembly is the issue for the failure of this specific unit. That is what has me asking the question. If we've got rigs out there with 40,000 miles use on and off road without failure, then just doing a correctly setup rebuild with high quality parts would be fine. I don't mind doing a thorough job once.
From my time reading the BMWMOA ON from the time period, the biggest reason for the failures was shimming of the bearing. A PRECISE measurement of the spacing was required and then a PRECISE shim thickness was required.
Of course, Anton will likely tell me I'm off my meds, but that's what I remember from the time.
Illegitemi non carborundum est!
