Rear drive failures. Is BMW alone?

[John Ranalletta]

Anyone know how other makes are doing with rear drive failures?

 

Also, I'm not an engineer, so I tend to think in simple terms as has been oft pointed out; however, every one of our cars has a bearing at each corner. Each of them bears up under a helluva lot more stress than the rear drive bearing in a motocycle. They have to operate all year in conditions motorcycles don't like ice, snow and salt while enduring more side loading and bearing more weight than the bike's rear drive.

 

Is the BMW rear drive another example of German arrogance in engineering? I experienced it at great cost in an early Jetta. Perhaps they should ask Yamaha to design and supply a rear drive unit.

 

Paying almost $20k for a bike that has this record of continued failure is just nuts.

[russell_bynum]

There is no problem. There has never been a problem. And anyway...they fixed the problem with the new FD design on the R1200's.

[John Ranalletta]

There is no problem. There has never been a problem. And anyway...they fixed the problem with the new FD design on the R1200's.

When I think that one of this board's most iconic and beloved members got stranded twice in row, I don't think I'd bet a once-in-a-lifetime-two-week vacation on the BMW rear drive.

 

Sure, sure, sure. Any bike can fail, but not with such proven reliability. BTW, do other makes implement an HES that's out front of the engine and susceptible to rain as BMW does?

[notacop]

Don't know about the 1200, not having one but old 'R' bikes ate splines. Couldn't make the wheel spline softer, it was too easy to replace.

1100 rear ends are becoming trash pile fodder after extended miles. May have to do with the single sided swing arm. Lotta stress there.

[smiller]

There is no problem. There has never been a problem. And anyway...they fixed the problem with the new FD design on the R1200's.

You left out: 'And the number of reported problems don't really mean anything anyway, it's just an illusion.'

[russell_bynum]

There is no problem. There has never been a problem. And anyway...they fixed the problem with the new FD design on the R1200's.

You left out: 'And the number of reported problems don't really mean anything anyway, it's just an illusion.'

 

There is no illusion because there have been no reported problems, because there is no problem.

 

If there were any problems, it is because of owner neglect and abuse.

 

And besides...they fixed the problems with the new final drive design.

 

 

 

 

[Whip]

I just went through the last several months of FJR complaints......no final drive failures.

 

That doesn't mean it hasn't happen, but.................

 

Whip

[smiller]

There is no illusion because there have been no reported problems, because there is no problem.

Jawohl!

[Jerry Johnston]

I know of an ST1100 that had a bearing failure in the rear end at approx 90k miles.

[flat_twin]

Anyone know how other makes are doing with rear drive failures?

 

Also, I'm not an engineer, so I tend to think in simple terms as has been oft pointed out; however, every one of our cars has a bearing at each corner. Each of them bears up under a helluva lot more stress than the rear drive bearing in a motocycle. They have to operate all year in conditions motorcycles don't like ice, snow and salt while enduring more side loading and bearing more weight than the bike's rear drive.

 

Is the BMW rear drive another example of German arrogance in engineering? I experienced it at great cost in an early Jetta. Perhaps they should ask Yamaha to design and supply a rear drive unit.

 

Paying almost $20k for a bike that has this record of continued failure is just nuts.

 

Prior to the R1100 series, rear drive failures were quite rare. BMW started using single sided swingarm design in the mid eighties with the first K bikes and the last generation airhead boxers. Those bikes didn't have the rear drive problems like the 1100/1150's.

[Mike05]

Got a call today from a friend in Kansas City;

his Honda Valkyrie's final drive failed 600 miles after coming out of the dealer for a tire change.

 

We're soooooooo lucky BMW's don't have issues like that!!

[Bill_Walker]

There is no illusion because there have been no reported problems, because there is no problem.

 

 

"These aren't the final drive failures you're looking for."

 

 

I guess the remnants of the Jedi Knights work at BMWNA. Obviously ones who've gone over to the dark side!

[HexHead]

There is no problem. There has never been a problem. And anyway...they fixed the problem with the new FD design on the R1200's.

When I think that one of this board's most iconic and beloved members got stranded twice in row, I don't think I'd bet a once-in-a-lifetime-two-week vacation on the BMW rear drive.

 

Sure, sure, sure. Any bike can fail, but not with such proven reliability. BTW, do other makes implement an HES that's out front of the engine and susceptible to rain as BMW does?

 

I can't help but wonder about something. Supposedly the new FDs are maintenance free (although BMW now does a fluid change at 600 miles), yet many here are taking it upon themselves to change the fluid. Maybe this has something to do with the failures?

[Bud]

Why are the rear ends failing?

 

Lots of speculation but little hard data. At one time, IIRC, there was an attempt by members of this board to document failures and try to get BMW to address the issue.

 

Don't remember the results, if any.

[smiller]

I can't help but wonder about something. Supposedly the new FDs are maintenance free (although BMW now does a fluid change at 600 miles), yet many here are taking it upon themselves to change the fluid. Maybe this has something to do with the failures?

There is a job waiting for you at BMWNA.

[wrestleantares]

There is no problem. There has never been a problem. And anyway...they fixed the problem with the new FD design on the R1200's.

You left out: 'And the number of reported problems don't really mean anything anyway, it's just an illusion.'

 

There is no illusion because there have been no reported problems, because there is no problem.

 

If there were any problems, it is because of owner neglect and abuse.

 

And besides...they fixed the problems with the new final drive design.

 

 

 

 

 

From Iron Butt Rally Headquarters:

 

Unfortunately, Rob's chances of scoring the Homer, Alaska, bonus have just vaporized. His BMW R1200RT, the one with the all-new, never needs maintenance final drive, is puking rear end lubricant all over Public Highway 16.

[eakins]

There is no problem. There has never been a problem. And anyway...they fixed the problem with the new FD design on the R1200's.

 

i particularly like the reports/pictures of the 1200 FD catching on fire. this new design not only still fails but now burns. i had high hopes for the 2 bmws i owned and was very proud of them. i felt i owned the best, but come to realized that was a fleeting image from the airheads. i gave up some of the bmw luxuries to own a strom. it's dead relaible and truth be known way more fun to ride. i like to look at what bmw is producing, i'll never own one again.

[eakins]

Don't know about the 1200, not having one but old 'R' bikes ate splines. Couldn't make the wheel spline softer, it was too easy to replace.

1100 rear ends are becoming trash pile fodder after extended miles. May have to do with the single sided swing arm. Lotta stress there.

 

i think the single side swing arm is THE cause of the problem. sure it looks nice and wheel come off easier but all that load on a heavy bike just asks for failure. the Japanese FD just don't fail in any signicant numbers. they use a traditional rear layout and it works.

[motoguy128]

Anyone know how other makes are doing with rear drive failures?

 

Is the BMW rear drive another example of German arrogance in engineering?

 

Paying almost $20k for a bike that has this record of continued failure is just nuts.

 

Yes, I think they went too far. The single sided swing arm is cool, but I think too difficult to make reliable with the current manufacturing tolerances and a manual assmebly process.

 

Probably... but other bikes in it's class don't match to combination of comfort, features, fit/finish, engineering and performance. I think they will stubbornly continue with the current rear end design. To change it would be admitting failure. The ST1300 looked too cheap and didn't feel right. The FJR isn't comfortable enough and lacks character. I love my RT. Motorcycle are an emotional thing, you need to have a connection with your bike. The other bikes didn't do it for me.

[ShovelStrokeEd]

FWIW, the final drive on my Blackbird requires replacement at roughly 15 and 30K intervals. New chain every 15K, new chain and sprockets every 30k. Cost is about $130 for the chain and another buck or so for the sprockets. I do the work myself, about 2 hours for the big job, 1 for the little one.

 

My GS ADv had a final drive failure at 51K miles and 11 months. BMW replaced it for free. Total costs was a $50 tip to the wrench and $20 to the tow truck driver. AAA picked up the cost of the tow, a motel for the night and a rental car.

 

None of the 6 other BMW's I have owned in the last 15 years has had a rear drive failure. I do keep after the splines on my airhead and my Guzzi but, with their dual sided swing arms, I expect no bearing problems.

 

I just happen to think this is a poor design and until BMW bites the bullet and goes back to a dual sided swing arm, they are gonna continue to have problems. How friggin' hard is it to pull an axle?

[motoguy128]

BTW, do other makes implement an HES that's out front of the engine and susceptible to rain as BMW does?

 

I'm not aware of any other manufacturers that use the swingarm type front end. Moto Guzzi, BMW, Triumph, Buell Ducati are about the only companies that go outside the "normal" with motorcycle engine or chassis designs. The big 4 don't stray too far from the norm, and Aprilia and KTM have unique products, but fairly typical engine configurations.

 

I don't see how it's exposed to the elements any worse than a regualar fork, or the suspension components on a car. If anything, it's actually better protected since the shock itself is tucked away fairly high on the bike and out of direct spray.

[russell_bynum]

From Iron Butt Rally Headquarters:

 

Unfortunately, Rob's chances of scoring the Homer, Alaska, bonus have just vaporized. His BMW R1200RT, the one with the all-new, never needs maintenance final drive, is puking rear end lubricant all over Public Highway 16.

 

Nope. BMW doesn't have a problem with final drive failures. They never have. And besides, they fixed the problem in the R1200's.

[Bud]

Got a call today from a friend in Kansas City;

his Honda Valkyrie's final drive failed 600 miles after coming out of the dealer for a tire change.

 

We're soooooooo lucky BMW's don't have issues like that!!

 

How many miles on the bike?

[SHIMHEAD]

Please post a picture of your simulated roundel contact lenses! Ironic that they call it a FINAL drive!

 

SHIMHEAD

'06 R12RT

[russell_bynum]

[Bud]

Glenn Pancoast is the second victim of a rear drive failure on the all-new, never needs maintenance final drive on his R1200GS. But he will apparently be back on the road tomorrow.

 

Hmmmmmm........

[motoguy128]

How are these guys back on the road in 1 day? Do they have mecahnics following them? I'd think that was against the rules. Maybe I was right and they are carrying a spare final drive in their saddlebag.

[russell_bynum]

How are these guys back on the road in 1 day? Do they have mecahnics following them? I'd think that was against the rules. Maybe I was right and they are carrying a spare final drive in their saddlebag.

 

If I were running the IBR on a BMW, I'd have a spare final drive either on the bike with me, or in a shipping box at home ready to go so all I have to do is call home and say "send it to this address".

[smiller]

If I were running the IBR on a BMW, I'd have a spare final drive either on the bike with me, or in a shipping box at home ready to go so all I have to do is call home and say "send it to this address".

I do that (keep a spare FD, among other parts, at home ready to be shipped if necessary), and I don't even have an iron butt.

[russell_bynum]

If I were running the IBR on a BMW, I'd have a spare final drive either on the bike with me, or in a shipping box at home ready to go so all I have to do is call home and say "send it to this address".

I do that (keep a spare FD, among other parts, at home ready to be shipped if necessary), and I don't even have an iron butt.

 

When I sold the RT, I was very close to keeping it, pulling the final drive, transmission, and ABS, parting out the rest, and keeping those bits for Lisa's RS. In the end I decided it was more trouble than it would be worth given the relatively low miles that we ride. I hope that turns out to be a good bet.

[smiller]

The way I look at it banking parts is really a no-lose situation. If you need them then you'll save a lot of money and inconvenience by having them on hand, and if you don't you will always be able to sell them for about what you paid... good used oilhead parts are almost as good as cash...

[Bud]

If I were running the IBR on a BMW, I'd have a spare final drive either on the bike with me, or in a shipping box at home ready to go so all I have to do is call home and say "send it to this address".

I do that (keep a spare FD, among other parts, at home ready to be shipped if necessary), and I don't even have an iron butt.

 

That's interesting. What comment, in any, does it make about the quality of the bike that you feel it a necessity to stock spare parts in your garage?

[smiller]

That's interesting. What comment, in any, does it make about the quality of the bike that you feel it a necessity to stock spare parts in your garage?

It says that I recognize that the bike has a few known weaknesses and am willing to plan around them. If you want to ride a bike (any bike) past 100k then that's something you just need to deal with.

 

To the eternal question of 'is a BMW as reliable as a Honda?' I'd have to say I don't really know... I'd guess not but then again I never attempted to keep any of my Japanese bikes this long. In the case of the 1100 though I have learned what is bulletproof (most of it) and what fails (almost always the same few things.) For me it is a fairly easy and inexpensive proposition to address those few things since I know how to fix them all, and thus they don't concern me much. A big advantage of any 10+ year-old design.

 

But FWIW for the same reason I wouldn't touch something as complex as the newer BMW bikes with a ten-foot pole, at least not yet. The devil you know is a lot better than the devil you don't. Maybe in ten years...

[Lone_RT_rider]

If I were running the IBR on a BMW, I'd have a spare final drive either on the bike with me, or in a shipping box at home ready to go so all I have to do is call home and say "send it to this address".

I do that (keep a spare FD, among other parts, at home ready to be shipped if necessary), and I don't even have an iron butt.

 

I replaced my FD at 85K and it was still good. Therefore, I too have an FD at home waiting to be shipped.

 

Shawn

[smiller]

Therefore, I too have an FD at home waiting to be shipped.

We probably shouldn't be making this information public...

[motoguy128]

What's sad is what these pasts say about part availability and the dealer network. It is defnitely a weak spot for the brand. It made that FJR at a Yamaha dealer 200 yards from my BMW dealer look tempting... knowing that the Yamaha dealer just over 1 mile from my house could service it. Hell, I could push it there if needed. Heck the Kawasaki dealer is only 3/4 mile away. I once dropped off my ZX9R and walked home.

[Bud]

That's interesting. What comment, in any, does it make about the quality of the bike that you feel it a necessity to stock spare parts in your garage?

It says that I recognize that the bike has a few known weaknesses and am willing to plan around them. If you want to ride a bike (any bike) past 100k then that's something you just need to deal with.

 

To the eternal question of 'is a BMW as reliable as a Honda?' I'd have to say I don't really know... I'd guess not but then again I never attempted to keep any of my Japanese bikes this long. In the case of the 1100 though I have learned what is bulletproof (most of it) and what fails (almost always the same few things.) For me it is a fairly easy and inexpensive proposition to address those few things since I know how to fix them all, and thus they don't concern me much. A big advantage of any 10+ year-old design.

 

But FWIW for the same reason I wouldn't touch something as complex as the newer BMW bikes with a ten-foot pole, at least not yet. The devil you know is a lot better than the devil you don't. Maybe in ten years...

 

Insightful. Thanks

[HexHead]

 

That's interesting. What comment, in any, does it make about the quality of the bike that you feel it a necessity to stock spare parts in your garage?

 

The dealer stocks spare parts. He's just cutting out the middleman.

[russell_bynum]

That's interesting. What comment, in any, does it make about the quality of the bike that you feel it a necessity to stock spare parts in your garage?

 

I'm not convinced that it is a quality issue. And some bikes go a zillion miles without final drive failures.

 

Mine went at 28K. The replacement is still going strong with over 60K on the clock. I know folks with 100K of VERY hard riding on the original unit.

 

My hunch (I'm not an engineer so this is just a gut feeling) is the design is probably borderline, and the tolerances are too big. When you get a "bad one" and the tolerances are at the outer edge of the spec, you have problems.

 

For the type of riding we do, I don't keep a spare final drive in the garage. (If I came across a really cheap one I might buy it just to have, though.) But...the IBR represents a pretty substantial investment in time and money for the participants. If I were competing, I'd want to take whatever precautions I could to ensure I could recover.

 

Since there have been a large number of BMW's DNF out of the IBR in the past few years with final drive failures, I'd make damn sure I was prepared to deal with that.

[Bud]

That's interesting. What comment, in any, does it make about the quality of the bike that you feel it a necessity to stock spare parts in your garage?

 

I'm not convinced that it is a quality issue. And some bikes go a zillion miles without final drive failures.

 

Mine went at 28K. The replacement is still going strong with over 60K on the clock. I know folks with 100K of VERY hard riding on the original unit.

 

My hunch (I'm not an engineer so this is just a gut feeling) is the design is probably borderline, and the tolerances are too big. When you get a "bad one" and the tolerances are at the outer edge of the spec, you have problems.

 

For the type of riding we do, I don't keep a spare final drive in the garage. (If I came across a really cheap one I might buy it just to have, though.) But...the IBR represents a pretty substantial investment in time and money for the participants. If I were competing, I'd want to take whatever precautions I could to ensure I could recover.

 

Since there have been a large number of BMW's DNF out of the IBR in the past few years with final drive failures, I'd make damn sure I was prepared to deal with that.

 

What you said makes a lot of sense Russell. We tend to hear only of the failures. It would be interesting to know what percentage of bikes, by model, by year have experienced FD failures.

 

It's of no consolation, if you experience FD failure, to know that it only happens on 3% (entirely made up number) of all bikes. However, the other 97% are happy.

 

One thing we know for sure, the failure rate is not 100%, unless you believe the "two kind of riders" argument.

[velomoto]

... If I were competing, I'd want to take whatever precautions I could to ensure I could recover.

 

Since there have been a large number of BMW's DNF out of the IBR in the past few years with final drive failures, I'd make damn sure I was prepared to deal with that.

Hmmm, sounds like it'll soon be common to see BMW's competing in the IBR pulling around a trailer containing tools and a spare FD.

[velomoto]

The way I look at it banking parts is really a no-lose situation. If you need them then you'll save a lot of money and inconvenience by having them on hand, and if you don't you will always be able to sell them for about what you paid... good used oilhead parts are almost as good as cash...

Interesting thot... part out one's used bike for more $$$ than selling it whole!

[nrp]

The single sided swing arm is not the cause of these failures. That "feature" increases the stresses on the FD case, but shouldn't seriously influence the life of components inside. Nobody has said anything about cracked cases so I suggest we have to look elsewhere.

 

More suspicious is the unusual rear axle bearing arrangement inside, which consists of a tapered roller bearing being opposed by a deep groove large ID ball bearing. The bearings are preloaded against each other to provide the accurate center of rotation needed for a quiet gearset. Thermal expansion problems are minimized by the use of an aluminum axle to compensate for the aluminum case.

 

The gotcha in this setup is the bearing loads will be very critically dependent on their preload. It is a blind assembly and the preload measurement is not direct. There IS variation in bearings such that simple replacement isn't likely to get the correct preload on a field repair either unless careful measurements are made & the shims adjusted.

 

But I also have to wonder if the BMW new factory assemblies are all being done correctly, or if even the design specs are correct.

 

One has to assume the reluctance of BMW service to admit the possibility of any alternate fixes. Personally though, I'd favor an assembled drag torque spec (assuming the seals are not yet installed) to determine the correct preload.

[UberXY]

The single sided swing arm is not the cause of these failures. That "feature" increases the stresses on the FD case, but shouldn't seriously influence the life of components inside. Nobody has said anything about cracked cases so I suggest we have to look elsewhere.

 

More suspicious is the unusual rear axle bearing arrangement inside, which consists of a tapered roller bearing being opposed by a deep groove large ID ball bearing. The bearings are preloaded against each other to provide the accurate center of rotation needed for a quiet gearset. Thermal expansion problems are minimized by the use of an aluminum axle to compensate for the aluminum case.

 

The gotcha in this setup is the bearing loads will be very critically dependent on their preload. It is a blind assembly and the preload measurement is not direct. There IS variation in bearings such that simple replacement isn't likely to get the correct preload on a field repair either unless careful measurements are made & the shims adjusted.

 

But I also have to wonder if the BMW new factory assemblies are all being done correctly, or if even the design specs are correct.

 

One has to assume the reluctance of BMW service to admit the possibility of any alternate fixes. Personally though, I'd favor an assembled drag torque spec (assuming the seals are not yet installed) to determine the correct preload.

 

Thank you for the cogent technical explanation - first one I have read.

[codougd]

What you said makes a lot of sense Russell. We tend to hear only of the failures. It would be interesting to know what percentage of bikes, by model, by year have experienced FD failures.

 

It's of no consolation, if you experience FD failure, to know that it only happens on 3% (entirely made up number) of all bikes. However, the other 97% are happy.

 

One thing we know for sure, the failure rate is not 100%, unless you believe the "two kind of riders" argument.

 

Precisely. When I bought my last car I haunted the online forums, especially Consumer Reports and Edmunds. If I had not taken into consideration the fact that it is human nature to complain but not to praise, then I would not have purchased any of the brands that had forums. If the posters in the forums were to be believed, there were no reliable brands or makes.

 

What is missing is reliable, verifiable data across the entire population of bikes, something that won't happen in my lifetime. Until such a millennial event occurs, we'll have to go with our gut and anecdotal evidence from friends and forums like this one.

 

And face it, motorcyclists are romantics at heart. If I had been strictly logical, I would have purchased one of the Japanese sport tourers and saved $5k.

[smiller]

But I also have to wonder if the BMW new factory assemblies are all being done correctly,

Given that what data we do have (concerning the oilheads) indicates the failures to be clustered in time it would seem that sloppy initial assembly or manufacturing is a major factor. The same was true with spline failures as I remember. If a fundamental design issue was involved with these issues there would be a more random distribution of the problem(s).

 

I think if Hans was having a bad day when he assembled your final drive then it will eventually fail no matter what oil you use or what divining rod you wave at the thing. Luckily he seems to have many more good days than bad and most final drives (and entire bikes) last a good long time, but I wouldn't be at all surprised if BMW's lower reliability relative to the Japanese brands has to do with a simple lack of quality control during manufacturing and assembly and nothing more.

[Ken H.]

do other makes implement an HES that's out front of the engine and susceptible to rain as BMW does?

Well that is one thing that probably truly is fixed in the 1200's as there is no longer a HES. Rather they have a traditional crankshaft position sensor in the block.

[velomoto]

Given that what data we do have (concerning the oilheads) indicates the failures to be clustered in time it would seem that sloppy initial assembly or manufacturing is a major factor. The same was true with spline failures as I remember. If a fundamental design issue was involved with these issues there would be a more random distribution of the problem(s).

 

I think if Hans was having a bad day when he assembled your final drive then it will eventually fail no matter what oil you use or what divining rod you wave at the thing. Luckily he seems to have many more good days than bad and most final drives (and entire bikes) last a good long time, but I wouldn't be at all surprised if BMW's lower reliability relative to the Japanese brands has to do with a simple lack of quality control during manufacturing and assembly and nothing more.

Two other possible explanations/causes:

1. Inconsistent supplier quality. This was the explanation given for the recall on my 12RT's transmission: "bad batch of parts from a supplier".

 

2. Simplicity of design for manufacture/assembly. One of the reasons given for the higher quality of Japanese cars over American cars was the engineering of the Japanese cars provided simpler assembly which ended up producing a more reliable product. Guess the idea is to keep it simple for Hans!

[motoguy128]

BMW's competing in the IBR pulling around a trailer containing tools and a spare FD.

 

Why not just tow a spare bike. that way you won't loose time repairing the failure.

[James Clark]

Please post a picture of your simulated roundel contact lenses! Ironic that they call it a FINAL drive!

 

SHIMHEAD

'06 R12RT