R1200RT Rear Drive Failure

aaaaaa said:

I disagree with the notion that since it was someone elses failure it's not a problem. It disturbs me when a service manager at a BMW dealership tells me that the internet is comprised of a bunch of malcontents who complain about non factual problems.

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Exactly!

I once mentioned a very long time ago that a rear drive failure or any other failure that could cause loss of control of the vehicle, should be reported to the DOT - Safety Department. Sure enough, it has been brought up on an ADV Rider thread.

If these number of failures are common place, maybe the dealer can tell us why camshaft or valve seat failures aren't as common; in fact, you never hear about them...cause they don't exist in any numbers.

Rear Drive Fire

I had a rear caliper sieze up at 70mph, new R1150GS, and it caught the final drive on fire. Helluva mess. Fixed under warranty

GlobalRider said:

snip
If these number of failures are common place, maybe the dealer can tell us why camshaft or valve seat failures aren't as common; in fact, you never hear about them...cause they don't exist in any numbers.

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You weren't around in '81 thru '84 I take it...

... on second thought...

Mmmm, on second thought, I guess I'll stick with my (almost maintenance free) 1100RT, a bit longer...wj

It is my understanding that the NHTSA has a "critical mass" number for reports. It may be five or twelve or some other number. Reports for identical issues are simply "anecdotal, isolated, anomalies" until the "critical mass" number is reached. In other words, if your BMW rear end breaks, camshaft, timing belt or some other part that is not a "normal-wear part" breaks, REPORT it. Not until the NHTSA forces BMW to make changes will changes occur.

Anybody remember the exact failure stats from the Iron Butt Rally before the past one. BMW motorcycles represented something like (pulling numbers out of my butt) fifty percent of the entries and ninety percent of the DNF due to motorcycle failures, mostly rear ends and timing belts (IIRC). Did anyone who suffered a failure during that rally report it?

Drag BMW's "qwality" department kicking and screaming into the twenty-first century. Otherwise, the marque will go the way of the Dodo. (Which, the way things ARE, may not exactly be a bad thing.)

After 8 weeks of vacation in Germany

nrpetersen said:

Now THAT is an unmitigated quality problem. Has BMW been having labor problems?

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they probably forgot what goes where!

Flash, one comment. I have a gut feeling the fault does not rest with BMW's "Qwality" department. Their job is (should be) to ensure the stuff coming in from external vendors meets all of the engineering specifications. I am afraid the rear-drive issue is a result of a flaw in the product-development process. Somehow, prototypes of these rear drives were not subject to the same stresses and environments now being seen in the real world - assuming of course they were failure-free and deemed perfectly acceptable during product development. (Either that, or problems were encountered and somebody signed off on them anyway... that's not the Qwality Dept either)

soffiler said:

Flash, one comment. I have a gut feeling the fault does not rest with BMW's "Qwality" department. Their job is (should be) to ensure the stuff coming in from external vendors meets all of the engineering specifications. I am afraid the rear-drive issue is a result of a flaw in the product-development process. Somehow, prototypes of these rear drives were not subject to the same stresses and environments now being seen in the real world - assuming of course they were failure-free and deemed perfectly acceptable during product development. (Either that, or problems were encountered and somebody signed off on them anyway... that's not the Qwality Dept either)

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Fair enough. But... shouldn't the quality department be involved in signing off all process documents for the engineering-design department? Clearly BMW has a rear drive differential design and release process that is 3rd-world class and has been for a LONG time. Even the F650CS had bad rear sprockets upon initial product release. Seems like somebody at BMW needs to fire their drunken brother-in-law and hire someone competent to do the job.

Update on R12 Repair

I have to say that things have gotten better since my initial interaction with Tony.

Marek (or Mark if my ears are not working well) called last week to let me know the parts were in transit to the dealer. The dealer and I spoke on Friday and they were aware from BMW NA that the final drive was being shipped to them. It is supposed to arrive on or after Wednesday. You or I could ship something from Germany to Eugene, OR overnight if we were so inclined and for enough money, but this part will take five days to wend it's way to Eugene. Could be slow shipping or could be the need to clear customs in New Jersey before proceding to Eugene. Remarkably no one in a position to explain that has offered an explanation!

Anyway, replacing the rear end seems not to be a big deal and there is some chance the bike might be returned to me on Friday or Saturday of this week. However that's probably optimistic. My guess is next week is more likely. We'll see.

Apparently many hexhead owners are experiencing delays in obtaining parts to repair their bikes. The BMWSportTouring forums are filled with such stories. Weeks and weeks waiting for electronics, mechanical parts, and sometimes difficult diagnosis work. Even waiting for the second year of production has not helped many of us avoid the startup costs associated with new models.

I'll be sure to post a final update when I pick up the bike. Thanks again for all the kind words.

Those of you who think the new final drive is not working out well for the company or it's customers might be interested to know that the Germans have a word for such a situation. They call it, "Schlimmbesserung". Literally this is an "improvement that makes things worse." Let's hope the new parts are really besser unt nisht schlimm!

-Gary

Final Status Update

As promised the final chapter in the story is being posted here.

Last week a replacement final drive was supposed to arrive on Wednesday (9/27). The dealer had blocked out time based on information from BMW NA. The part never showed up. The tracking information didn't work. No explanation.

I called BMW NA to ask, "what next?" The reply was that another part was being shipped but would not show up until at least 10/5. So they authorized the dealer to canabalize the final drive from a bike on the showroom floor.

Unfortunately by the time they had done this the dealer had lost their time slot and was short handed for a few days. They finally got to it yesterday and called to arrange delivery. They were coming up to Portland to drop off and pick up bikes anyway and offered to drop my bike off at the house.

As of yesterday they still had not received the new final drive.

Assuming the bike arrives today the total elapsed time since failure of the final drive to having the bike back in service has been 3 weeks and 5 days (26 days). I had to cancel my long planned September vacation and have missed the last month of nice riding weather. The rains will start anytime now in Oregon.

I won't go into all the myriad details and explanations for the delays and lack of parts. Suffice it to say that the dealer was frustrated, too, would have been happy to have me back on the road much sooner. BMW simply doesn't have a working process in place to repair failed final drives. I understand they are working on a new approach to managing final drive failures, but until that process is in place and parts are inventoried it won't do customers any good.

Keep an eye on rear wheel lateral free play. There should be none. Pay attention to burning smells and evidence of oil on the rear wheel (like excess dirt adhesion). If you are unlucky enough to experience a final drive failure and run into the lack of parts for repair be sure to call BMW NA at 201-263-8233 (I had to get this number from the Oregon Attorney General's office).

Be polite and constructive with everyone you deal with and remember that your dealer can't make parts appear by magic, but rather is depedent on BMW to provide a repair solution for these failures.

If you do have final drive failure I recommend reporting this to NHSTA via their web safety complaint form. This is easy to do and will allow them to determine if there is a pattern of failures. There is a safety component to these final drive failures which can't be ignored. The URL for initiating a complaint is http://www-odi.nhtsa.dot.gov/ivoq/

Ride safe,

-Gary

PS - I suppose I had better update my .sig now...

That's a disappointing story Gary.

This week I drained the final drive oil from my replacement. It had 430 miles on it. The oil was really dirty-lots of suspended black material, but only a small amount of fine steel on the magnet. Replacing the oil at 600 miles as BMW now recommends seems like a really good idea.

Where does the black debris come from? Is a shaft or axle seal wearing? I don't think it would be from bearing or gear tramp metal.

We need to start putting thermometers on these rear drives to spot impending failures. I have not found an appropriate one yet though.

nrpetersen said:

Where does the black debris come from? Is a shaft or axle seal wearing? I don't think it would be from bearing or gear tramp metal.

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Is it black bits of debris or is your gear lube black?

nrpetersen said:

We need to start putting thermometers on these rear drives to spot impending failures. I have not found an appropriate one yet though.

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Somebody already mentioned how hot the casting of their rear drive was after a ride.

I just felt mine after a 500 km (300 mile) day ride. It was no hotter than room temperature with an outside air temperature of 55 to 60??F.

Maybe a stick on unit as found on aquariums would work, but with a higher range.

sarmand said:

This week I drained the final drive oil from my replacement. It had 430 miles on it. The oil was really dirty-lots of suspended black material, but only a small amount of fine steel on the magnet. Replacing the oil at 600 miles as BMW now recommends seems like a really good idea.

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That looks like molybdenum disulphide to me. How about having it assayed?

jdiaz said:

That's a disappointing story Gary.

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You're right, Jon. I wish it were otherwise.

Good news! The bike was delivered back to my house right on time. It was good to see the bike again and to ride it around the block. Hopefully I'll get to go for a ride sometime this weekend.

BTW over on the BMW bulletin board at the BMW USA site there is a story by an owner of an F650 (late model) who is having the same sort of problem getting an engine controller. Sounds like an even worse flavor of my experience.

For your safety, check it yourself

Has anyone addressed the idea that maybe an individual group or production run of rear ends or parts for assembly, made or assembled at the same time, might be the culprit? Even a bad torque wrench or torque setting on the assembly line could cause early failure, by an incorrect preload torque of the axle bearing nut adjustment. Maybe all the failed parts came off the same shelf, but at different times, for different assemblies. BMW should have a Quality Control that is out of this world for the price that they ask for their bikes. This is not an excuse, but maybe somewhere to start looking for an answer for the intermittent failures.

If it was a engineering design flaw, then shouldn't they all have failed? A few this year, a few last year and so on, even a few on different models, is one thing. Murphy's Law will always prevail. But it's a safety issue and needs to be reported by the bike owner, even if he does his own repairs!

Make a 'Personnal Safety Rule' for yourself and before every ride or so, while your checking your tire pressure, throw the ol girl up on the centerstand and check the rear for axle looseness by pushing and pulling on it from side to side, at the 9 and 12 o'clock positions. Also, rotate the wheel a few times and check for any drag or play from bearing failure. Have a friend sit on the back of the bike or just weight it down until the front tire just comes off of the pavement and check the front the axle the same way. It only takes about 2 minutes to do the whole PM check and if you find a problem, for your safety, park it until it can be fixed.

Rear End Failure

"Has anyone addressed the idea that maybe an individual group or production run of rear ends or parts for assembly, made or assembled at the same time, might be the culprit?..."

Gary:

When did you buy your '06 RT, or a better question would be when exactly was it made?

Easy
Kerrville, Texas

An engineering or design flaw does not have to be obvious or even failure prone all the time. It could have simply been a marginal mistake on component design or material composition that fails when the individual critical point is met. Not all riders might hit that point due to differences in load, riding style and mileage.

It should not be carried over to succeeding years once the item starts to fail. It should trigger an immediate investigation by the design team as to what the problem is and eliminate the design point that causes it. At least one would hope that would be the case.

Some thoughts from a retired mech engineer (having been there, done that, a few too many times....) -

It could be bad bearings - but there from what I read, there seem to be individual bad axle assemblies that won't stay fixed.

It could be underdesigned for the task - but then there would be many failures at very roughly (order of magnitude that is) the same mileages, because the likely loading spectrums can't be that different between drivers.

It could be a bad design - it is frankly unusual having a large ID ball bearing opposed by a tapered roller bearing, but I don't see that as necessarily bad providing the clearances & preloads are set up right.

It could be it needs a special lubricant - but then the primary variation would be miles-to-failure. The failures would generally be to the gears (when the anti-wear additives give out), not the bearings. The failure distances seem too varied for that & the benefits of exotic lubricants over more conventional antiwear oils are not that significant.

It could be oil breakdown or excessively viscous oils but the failures don't seem to be related to high (or low?) ambient temperature operations from what I can see of the poster locations.

It could be variations in assembly preloads - then manufacturing tolerances of the special parts would accumulate such that replacing the bearings (which are generally only fair at being identical) would have a marginal chance of success. The assembly includes shims to take care of this, but the shim selection would be critical. I sense that many shops just use the same shims assuming the bearings are identical. That is a mistake. The shim selection should be done using a dial indicator to measure clearance as individual bearings can and will vary in their thrust dimensions. The shim increment used (.002 inch?) does seem pretty coarse.

Bearings with an excessive preload will not roll noticeably harder. Forget about that check. Only if they are substantially overloaded will they even run hot, but it is the only preload indicator we have short of disassembly and measurement. Operating temperature rise might be another indicator though.

Gears are very critical on the locations of the operating centers and rotating axes alignment. This is probably why there is some preload involved. Get it wrong (i, e, loose) and they will get very noisy. But within limits, even noisy gears can last a long time.

It seems the initial failures are bearing related. The gears fail only when the bearing debris grinds the gears up (right?).

There has been some talk of "black stuff" that I can't explain except that fine metal debris can appear black. A magnet should establish what it is.

NRP