Final Drive Failure at 9300 miles

[b34cez]

Unfortunately, I have to join the club of final drive failure early, at 9,300 miles (15,000 km) with a 2008 R1200RT serviced before time.

Before the third regular maintenance, I have checked and found considerable rear wheel play. The dealer recognized the failure and it is going to be solved in warranty.

Still, at only 9,300 miles ...

[BanjoBoy]

I'm sorry to hear this. Only 9,000 mi.? That's unbelievable! Makes me wonder if I'm not riding a grenade? Every year I keep thinking the newer models are getting better, but then I'm proven wrong.

Bummer dude!

[RichEdwards]

My buddy Jeff had his final drive die just after the Unrally (and 1200 miles from home.) His bike had 70,000 miles on it and was out-of-warranty. Repair cost was just under $800.

[T__]

b34cez, yes, BMW still isn’t out of the woods on these final drive failures yet.. A guy local to my area here has had (2) final drive failures on his 2009 RT in less than 6,000 miles (yes! that is UNDER 6,000 miles total on the motorcycle)..

 

BMW finally authorized a new final drive install AFTER the 2nd failure..

 

 

Twisty

 

[smiller]

Are these failures mostly for the same cause and if so do we have any inkling as to what that cause might be? For instance the oilhead failures seem to be for the most part due to crown bearing issues... is there a similar common cause for early failures in the current design?

[Twisties]

I can say that as of a year or so ago I was well and truly convinced that there were multiple failure modes. I had thought more recently the changes in maintenance, etc had largely fixed the problem, though was holding my breath for this year's riding season. Now, I'm thinking maybe not as much improvement as I had thought. Although, we're still nowhere up to the ten or 20 reports we might have had in 2007. It will be interesting to see if some of the changes have reduced or eliminated some failure modes, but not others. Some involved non-lubricated parts IIRC. It will be interesting to see if the failure modes still look the same, or if we see significant change.

[T__]

Seth, the guy in my area failed 2 crown bearings.. The crown bearing in the hexhead doesn’t run in the gear oil (they are pre-greased & sealed on both sides)..

 

I didn’t see the bearings myself but he said the first one looked like it was run hot.. Even he didn’t see the 2nd bearing as dealer kind of kept it quiet..

 

He asked the dealer had they measured either the bearing bore or the ring gear axle & they said no so my (limited knowledge) guess would be a tight bearing due to tight bearing bore or oversized ring gear axle.. (no side preload on the heaxhead crown bearing)

 

Twisty

 

[smiller]

Well if the failures are primarily due to crown bearing issues and these are indeed sealed units then lube (meaning gear oil) probably wouldn't be much of a factor in the failures. And if the bearings are sealed that might explain why BMW originally felt that a 'lifetime' fill was adequate.

 

So I guess the question is are these failures due to parts tolerance issues or an underdesign regarding the bearing itself? And if the former then one would wonder whether merely replacing the failed bearing would be any kind of a long-term cure...

[T__]

Are these failures mostly for the same cause and if so do we have any inkling as to what that cause might be? For instance the oilhead failures seem to be for the most part due to crown bearing issues... is there a similar common cause for early failures in the current design?

 

 

Seth, The earliest heaxhead final drive failures were not really final drive related but were with press fit issues of the wheel drive flange on it’s splines (a final drive related failure that usually got reported as a final drive failure)..

 

Then there seemed to be a rash of pinion bearing failures so BMW upped the pinion bearing sizes sometime in mid 2006..

 

Then there were still some random final drive issues (I have no idea what) so BMW started the final drive gear oil change at 600 miles & now at major service intervals.. (so much for the filled for life)..

 

Now lately there seems to be a few crown bearing failures.. (not as bad as the oil heads though)..

 

Twisty

 

 

[smiller]

Thanks, that info clears things up a bit.

[T__]

Clip~ So I guess the question is are these failures due to parts tolerance issues or an underdesign regarding the bearing itself? And if the former then one would wonder whether merely replacing the failed bearing would be any kind of a long-term cure...

 

Seth, maybe we will get some feed back on this as time goes by.. It looks like BMW is now letting the dealers go into the final drive to repair them.. Early on BMW just simply replaced the failed final drives & captured all the failed units so even the dealers had no idea what was going wrong..

 

Twisty

 

[Tony_K]

This subject causes me to wonder how other manufactures of single sided rear drives fair? What are their failure rates? Since I have never took time to investigate, I have no clue. If it's less than what we see in BMW's why would that be, since there can't be that much difference in the overall construction... or can there be.

 

Sorry, just a meandering query.

[Bluecone]

this link might help?? For what it's worth

 

http://www.advrider.com/forums/showthread.php?t=29360

[Ken H.]

This subject causes me to wonder how other manufactures of single sided rear drives fair? What are their failure rates?

But I think you raise a good point. The single sided looks sexy, and makes wheel service easy, but it also subjects the crown bearing to tremendous side loads. Personal opinion – it’s a herculean task to make the design concept work.

[ollka]

it’s a herculean task to make the design concept work.

 

Just like in every car - not so difficult (if really trying to make it last instead of cheap as possible)

[Froy]

but it also subjects the crown bearing to tremendous side loads. Personal opinion – it’s a herculean task to make the design concept work.

 

But they have used this design on cars for 100 years! They also have side loads. Why shouldn't it be reliable on a bike coming from an experienced company?

[T__]

'08 RT, (most) cars are not much of a comparison as they use wider bearing spacing due to long axle shafts.. Long axles shafts lengthen out the twisting moment on the outer bearing..

 

Now some of the older independent suspension cars like the early Corvettes used a similar rear set up but the ring & pinion load was remote to the wheel loads so the cornering load wasn’t coupled to the ring/pinion side thrust loads.. Even so they did have a fair amount of rear wheel bearing failures..

 

Then you have some of the newer front wheel drive cars (narrow bearing spacing & deep groove ball bearings).. Some of those have had a higher bearing failure rate than the BMW motorcycle.. All kinds of different reasons for the failures-- from bearing quality issues,, to excess side loading,, to tight fit due to axle size or bearing bore being out of spec,, to water intrusion issues,, to even some static electricity issues in dry humidity areas,, to sharp impact loadings (like high tire pressures & square edged pot holes),, to some we just don’t understand what happened..

 

 

Twisty

 

[Ken H.]

it’s a herculean task to make the design concept work.

 

Just like in every car - not so difficult (if really trying to make it last instead of cheap as possible)

But how much does a cage wheel have to lean over compared to a bike one? Think about the top point to bottom point tremendous opposite direction side force delta on the crown bearing on our bikes when cranking around a high-speed sweeper leaned over to knee dragging. I'm amazed as many of them hold together as do!

[Albert]

it’s a herculean task to make the design concept work.

 

Just like in every car - not so difficult (if really trying to make it last instead of cheap as possible)

But how much does a cage wheel have to lean over compared to a bike one? Think about the top point to bottom point tremendous opposite direction side force delta on the crown bearing on our bikes when cranking around a high-speed sweeper leaned over to knee dragging. I'm amazed as many of them hold together as do!

 

Hmm, I would agree the loads seen by wheels from a car are different from a motorcycle but I'm not sure what you're describing. I would think the loads induced via a motorcycle chassis would primarily be in the plane of the wheel (even when leaned far over). A 4 wheeled vehicle being driven agressively could have an out of plane moment induced at the traction limit almost continuously. Maybe I misunderstood.

[T__]

Ken, I would imagine a lot LESS cornering side force on the motorcycle wheel bearing than an automobile..

 

With the bike leaned way over you are compressing the suspension so you are trading tire & bearing side load for tire & bearing vertical load.. That is one reason you can corner so hard on a motorcycle.. If you could somehow find a way to corner a motorcycle standing up without leaning it over then probably higher cornering bearing side loading..

 

 

On the other hand a good portion of automobile cornering load (assuming a decent cornering G loading) is taken by a vertical wheel so the bearing lateral loading is probably pretty high..

 

On a motorcycle- high cornering G forces pushes the rider into the seat not throwing you off or across the seat..

 

In a car- high cornering forces wants to slide the driver across the seat not into the seat..

 

Twisty

 

[Twisties]

Ken, I would imagine a lot LESS cornering side force on the motorcycle wheel bearing than an automobile..

 

With the bike leaned way over you are compressing the suspension so you are trading tire & bearing side load for tire & bearing vertical load.. That is one reason you can corner so hard on a motorcycle.. If you could somehow find a way to corner a motorcycle standing up without leaning it over then probably higher cornering bearing side loading..

 

 

On the other hand a good portion of automobile cornering load (assuming a decent cornering G loading) is taken by a vertical wheel so the bearing lateral loading is probably pretty high..

 

On a motorcycle- high cornering G forces pushes the rider into the seat not throwing you off or across the seat..

 

In a car- high cornering forces wants to slide the driver across the seat not into the seat..

 

Twisty

 

I think I'd better go test this out, now....

[lvnvbiker]

The basic design principals are sound, and in fact used in numerous heavy(VERY HEAVY)equipment designs. Alot of the newer very large forms of equipment use independent hydraulic drives on independant suspension somewhat similar to the swinging arm on an RT. Of course there is a planetary system in the hub to ratio the power at each wheel but the basic design has the crown bearing and such, but they still handle loads of over 125 metric tonnes and applications of over 1000hp. I have no real idea of what causes the failures in the BMW design, but I have a couple hypothosis much of what has allready been brought up like incorrect bore and oversize outer race thicknesses where even a very small amount of load or minor deformation (causing load) on the bearings will generate heat and particulate in the sealed design causing it to fail. I'm sure that there are many other factors that very well could come into play also, but I am just a lowly mechanic and not an engineer so I'm not going to venture further into it. Thankfully mine has stayed together so far and has provided me with hour and hours of fun, and with any luck (the one thing I seem to be sorely lacking lately) it will provide many more. I feel for those that have had a failure, but it is a machine and they all do one thing very well sometime during thier usable life, they break. I accept this as fact, and have spent many years riding them like I had stolen them until they break, then repairing them and repeating the cycle until I get a different one. Looking on the bright side of the issue though BMW does seem to be taking care of it long after the warrantee has expired much to thier credit.

[RBertalotto]

This subject causes me to wonder how other manufactures of single sided rear drives fair? What are their failure rates? Since I have never took time to investigate, I have no clue. If it's less than what we see in BMW's why would that be, since there can't be that much difference in the overall construction... or can there be.

 

I'm a SSSA nut. In the garage I currently have a Honda VFR (I've owned four), MV Agusta F4s, and a BMW R1150RS. I've also owned two SSSA Ducatis over the last couple of years. Other than BMW, I've Never heard of a bearing failure on the other brands. And if you look at how they are designed, you could see why. They are basically designed like the front hub of an automobile. Very simple bearing designs. No big giant ball bearings trying to handle two loads at once.

 

And thanks for clearing up the load issue of bike VS automobile. Automobiles handle much higher horizontal loads than motorcycles due to weight, and lean angle........

[Tony_K]

So if what Roy is saying is correct, wouldn't it behoove BMW... the gods of LD motoring... to get with the program!?!

 

Being differnt is good, even great for some things but if there is a better, more reliable way to put your power to the tarmac ADOPT IT!

 

Jeeze... Be stubborn to a point but right the wrongs rather than perpetuate it.

[JayW]

So if what Roy is saying is correct, wouldn't it behoove BMW... the gods of LD motoring... to get with the program!?!

 

Being differnt is good, even great for some things but if there is a better, more reliable way to put your power to the tarmac ADOPT IT!

 

I am sure BMW executives, and many others, are following the later model BMWs in the Iron Butt Rally very closely. If there is another series of final drive failures this year like there was 2 years ago, then BMW is going to have to make some tough decisons to address their already tarnished repuation because of this issue. One BMW is already out of the competition, but not for this problem.

 

Jay

 

 

[b34cez]

My bike never left the asphalt (it was not designed to do so, considering the full wheel rims) and whereas the same final drive is used for GS/GSA, I wonder how does it cope with off-road.

This is my fifth bike, on all other bikes I have changed nothing except consumables (fluids, filter, chain, tires, brake pads and sparkplugs), although they were a lot older and considerable higher mileage.

I drive for 14 years and ride for 6 years. I have never changed a clutch in a bike or any of the cars that I had over time (two driven past 150,000 km.).

 

The 1200RT was bought new, it was run-in absolutely by the book, proper tire pressure on each check and constantly monitored, serviced before time at the dealer, on each final drive fluid change there was enough oil in the final drive before change, at 9,300 miles the brake pads are far from being worn and the tires would last another 3,000 - 5,000 km. probably but I am considering replacing them.

So I consider fair to assume that my riding/driving/maintenance habits are O.K.

 

Still, I can consider that it is human to make mistakes and one manufacturing default is acceptable, but if I shall be obliged to change the FD second time I shall make a mess out of this. I am properly documenting this first failure under a technical expertise done by a judicial technical expert just to be prepared in case the second occurs. I chose this premium bike over others for its re-known reliability so I expect nothing else.

 

Did any of you find any practice/maintenance habit official or non-official that would prevent a FD failure?

 

[Selden]

I'm a SSSA nut. In the garage I currently have a Honda VFR (I've owned four), MV Agusta F4s, and a BMW R1150RS. I've also owned two SSSA Ducatis over the last couple of years. Other than BMW, I've Never heard of a bearing failure on the other brands. And if you look at how they are designed, you could see why. They are basically designed like the front hub of an automobile. Very simple bearing designs. No big giant ball bearings trying to handle two loads at once.

But, as someone pointed out when I made a similar observation about my 1988 Honda Hawk (SSA), all of these motorcycles have chain drive, which permits a simpler rear drive.

[olddude53]

Whatever the reason, BMW has got to step up to the plate sometime on this. No other brand of shaft drive bikes has this problem. But it appears from their actions BMW doesnt really care.

This is like the newer Triumph bonnevilles, which were breaking rear spokes by the 100's if not 1000's. At least now they offer an alloy wheel but never admit to something wrong with spokes/design etc.

[Twisties]

Now didn't someone say BMW was quoted in a magazine as saying they would cover the FD's to 70k miles? Anyone have the reference? How is that playing out? Are folks getting that coverage?

[roadhome]

 

I like this one! Haven't been here in a long while (work, ugh). It's good to know the grey matter is still churning hard here. I'll keep sitting quietly to the side and listening.

[motoguy128]

Now didn't someone say BMW was quoted in a magazine as saying they would cover the FD's to 70k miles? Anyone have the reference? How is that playing out? Are folks getting that coverage?

 

I got hte impression from talking with the service manager at my local dealer... that if you do regular service at hte dealer... they will "go to bat" for you and get it covered. At least the parts, but maybe not the labor. thsi was mentioned when having my ABS fluid repalced at 2 years and 12,000 miles. 2 years is recommended, but the service manger mentioned that chainging it annually isn't a bad idea and would go a long way towards any good will repairs out of warranty. Personally, I still think 1 years is a short intervals for any brake system, unless you ride 10,000+ miles per year or use the bike on the track where it sees a lot of heat cycles. But that's off topic somewhat.