Final drive failure at 46K miles? Come on BMW...

[The Gorf]

I have given into the fact that I must ride the ONLY RT on the face of the planet that is an utter and complete pile of shit.

 

So the local dealership looks the bike over and make some comments about the final drive. I take it to a local chap who does independant work and he tells me that when he drained the fluid out of the final drive, it was pitch black and FULL of metal shavings. This on top of a rather disturbing grinding noise/feel coming from teh rear of the bike that I assume is the final drive.

 

So now at 46K miles I have to replace a 1000$ part. I am utterly shocked. Is this common?

 

At this point, as soon as it's replaced this bike is going on the block. There is no question in my mind this time.

[Redbrick]

Sorry for your problem....Seems like there is a rash of drive line problems happening......I tried to buy an extended warrantee for wife's '04 1150 and haven't had any luck.......Factory one runs out in June....

 

 

Did I miss it? What year is it, 1100 or 1150?

 

Phil.............Redbrick

[The Gorf]

it's a 2000 1100RT

[Redbrick]

This won't help except to let you know you aren't alone......If you haven't seen it here's some info from members on drive line failures from another thread......1100's have had more final drive failures in the total but that may be because they have more miles on them......Who knows the magnitude of these issues?........BMW does.......

 

http://www.rightspin.com/motorcycles/misc/mpf.htm

 

 

Phil.........Redbrick

[Limecreek]

I wouldn't be too hasty about selling so soon. Yes the final drive is a weak point on the previous generation R-series bikes, but I would not put the bike on the block if this is the only failure you've experienced.

 

Repair and ride....

[Joe Frickin' Friday]

So now at 46K miles I have to replace a 1000$ part. I am utterly shocked. Is this common?

 

Define common.

 

Seriously though, it would be interesting to hear what people consider to be an acceptable failure rate ("failure" meaning a part that did not survive to its designed service life, whatever that may be).

 

What is an acceptable number of commercial airliner crashes per year?

 

What is an acceptable number of cases of food poisoning per year?

 

What is an acceptable percentage of final drive failures?

 

I do not intend to compare the tragedy of air disasters with the inconvenience final drive failure; I do intend to point out that both are inevitable, and no amount of design review or preventive maintenance will eliminate them; we must accept some non-zero failure rate, or go broke trying for perfection. Unfortunately, the misery will not be equally distributed; a star-crossed few will suffer final drive failures, and the rest of us will enjoy a trouble-free ownership experience. (FWIW, my FD crapped out at about twice your mileage. Am I fortunate, or star-crossed?)

 

I've seen your history, and it seems you've had an unusual share of problems. Sorry for that. If it's any consolation, a new FD can be had for about $725 delivered from Chicago BMW; you just need to install it yourself. I know, $725 still pains the wallet, but it beats $1000.

 

Whatever you choose - a new FD, dynamite, or a classified ad - I hope you come upon happier times.

[Pappy]

I wonder how many oilheads reported stolen are found totaled and just happen to have bad final drives...

[Mr. Frank]

FWIW the rear drive bearing that replaces the one you have is beefier. Sometime around 2002 BMW made the switch. If you replace the rear drive, it should be unlikely to crap out.

[axabmw]

Is it worth checking the Clutch splines etc while it's off the road to prevent anything else going in the near future?

[GordonB]

Check out Beemer Boneyard they have FD units for $300-$400.

[flat_twin]

I have given into the fact that I must ride the ONLY RT on the face of the planet that is an utter and complete pile of shit.

 

So the local dealership looks the bike over and make some comments about the final drive. I take it to a local chap who does independant work and he tells me that when he drained the fluid out of the final drive, it was pitch black and FULL of metal shavings. This on top of a rather disturbing grinding noise/feel coming from teh rear of the bike that I assume is the final drive.

 

So now at 46K miles I have to replace a 1000$ part. I am utterly shocked. Is this common?

 

At this point, as soon as it's replaced this bike is going on the block. There is no question in my mind this time.

 

 

Mine failed last fall at 50k miles. Black murky gear lube, grinding noises. Rear seal puked in the parking lot. I had it repaired at the dealership for $270. New seal and bearing. Way cheaper than a new final drive. Unless you rode on and on while it was grinding, you shouldn't need a whole new final drive unit. Sorry you feel you have to unload your RT. Yes, failures like this are a pain in the ass and no it shouldn't have happened in the first place. But, I'll keep my RT because it I still thoroughly enjoy riding it, it keeps running better all the time, and the occasional repair bill is still way cheaper than the cost of a new bike and the depreciation hit of selling/trading your old bike.

[Davis]

While 46k is low mileage to have a final drive problem and I don't mean to make light of the original posters problem, it is important to put this in perspective. The entire final drive hasn't failed. A component in the final drive failed, most likely the large weight supporting bearing. Cost of new bearing and seal ~ $200. About the same cost as a set of sprockets and chain, which you would have changed twice on a chain drive bike.

[raysuf]

My final drive crapped out on me on my O4 RT with 14k mile. I was happy it was under warranty.

[Global_Rider]

 

Define common.

 

3000+ pound cars have rear drives that aren't that much bigger, yet last the life of the car. Like 300,000 miles or more.

 

Yeah I know, they don't have a single sided swingarm etc, but as much as I love my 4 BMWs (all reliable by the way - I do the maintenance), I won't go out of my way defending driveshaft and rear drive failures.

 

Single sided swingarm (Monolever) R80 G/S models didn't have that problem. So what changed?

 

When you read about repeated failures of one or two components, you know there is a problem. How often do we hear about con rods letting go, or pistons failing?

[Joe Frickin' Friday]

3000+ pound cars have rear drives that aren't that much bigger, yet last the life of the car. Like 300,000 miles or more.

 

The sales volume of cars can justify a lot more R&D expense. Compare how many oilheads motorcycles BMW sells with how many Civics Honda sells (1/100? 1/1000?). If you want the same reliability, you have to spend the same total $ on R&D, but then the cost per unit will go way up.

 

Single sided swingarm (Monolever) R80 G/S models didn't have that problem. So what changed?

 

different geometry, different bearings, more powerful engine, etc. All of that requires testing, testing, and more testing to ensure the final product performs as intended. Which brings us back to the limited R&D/testing budget again.

 

We're also getting back to the definition of "problem." IMHO, given that limited sales volume I mentioned, it's not reasonable to expect motorcycles (generally speaking) to be as reliable as cars.

[SageRider]

...About the same cost as a set of sprockets and chain, which you would have changed twice on a chain drive bike.

Who cares? Chains and sprockets are wear items. One knows that they will need to be replaced periodically over the life of the bike.

Last I was aware of, there is no scheduled replacement interval for final drive bearings.

Also, shaft drive systems are more expensive in the first place than chains and sprockets. Somehow I doubt that BMW is eating that difference in expense.

[ericfoerster]

Funny, I can't remember the last rear drive failure I saw over on the Kawasaki Concours site.

In fact the only real problem I ever see is people wondering why they don't get a million miles on a set of tires

[smiller]

The sales volume of cars can justify a lot more R&D expense. Compare how many oilheads motorcycles BMW sells with how many Civics Honda sells (1/100? 1/1000?). If you want the same reliability, you have to spend the same total $ on R&D, but then the cost per unit will go way up.

 

True, but there's also the fact that Japanese motorcycle manufacturers change their designs much more frequently than BMW (and thus have less time for R&D and less field experience with a given design) while at the same time managing to maintain a reputation for reliability.

[Redbrick]

Quote............

 

We're also getting back to the definition of "problem." IMHO, given that limited sales volume I mentioned, it's not reasonable to expect motorcycles (generally speaking) to be as reliable as cars.

 

____________________________________________________________

FJR, ST, Concours ?

 

Phil.........Redbrick

[lithoman]

It seems the 00 and 02 RT's have had their share of spline failures around 20k to 25k miles, Mine only has 5300 miles on her and I can only hope this does not happen to mine!!

[The Gorf]

Ok so for follow up, here's what has happened so far:

 

Last week I started to notice some grinding and a little noise coming from the rear drive. I took it to the shop, they said it was going bad. So I also took it to my mechanic for it's 48K service (a little early because of this) and he says the same thing. No problem, I order the part and wait. In the meantime I continue to ride on it because it's my primary source of transportation. Mind you I was told that a few days of riding would be ok.

 

So last night (3 days later) I was riding home on the local highway out to my town doing about 50mph and all of a sudden the griding get worse. Lots worse. In the time it took me to realize what was going on, it let out this painfully loude grinding squeal, the rear wheel utterly locked up and the bike started fish tailing badly. I managed to keep it under control and all of a sudden the tire starts to spin again which puts the whole bike into a near tank-slap condition. With the tire rolling again, I manage to nurse it to the shoulder just as it comes to a complete grinding stop again.

 

Welp so much for that.

[Frank Cloud]

The sales volume of cars can justify a lot more R&D expense. Compare how many oilheads motorcycles BMW sells with how many Civics Honda sells (1/100? 1/1000?). If you want the same reliability, you have to spend the same total $ on R&D, but then the cost per unit will go way up.

 

True, but there's also the fact that Japanese motorcycle manufacturers change their designs much more frequently than BMW (and thus have less time for R&D and less field experience with a given design) while at the same time managing to maintain a reputation for reliability.

 

Jump over to the ST site, how many final drive/spline failures do you see there? Hardly any, if any. I don't buy into the fact that limited R and D dollars equals a poor design.

[Redbrick]

Glad your unasked for decelleration turned out OK Geoff....Really scary....Surprised your post was so politely worded....Of interest: Did you notice your final drive being warm or hot to the touch earlier in this episode or did you smell anything?....You mentioned the noise.....

When you get that puppy fixed would be interesting to see pics of the gears if possible......

 

Phil............Redbrick

[No_Twilight]

In the time it took me to realize what was going on, it let out this painfully loude grinding squeal, the rear wheel utterly locked up and the bike started fish tailing badly. I managed to keep it under control and all of a sudden the tire starts to spin again which puts the whole bike into a near tank-slap condition.

 

When the rear came unlocked you're lucky you didn't high side. Apparently it came unlocked while the bike was pointed approximately forward. I'll try to make a mental note that if this ever happens to me I need to hit the rear brake hard and hold it locked until the bike stops or is at least pointed straight. Thanks for sharing your story and congrats on riding it to a stop. --Jerry

[leikam]

I'm shocked that your mechanic said it would be OK to ride it for "a few days" like that. Glad your little breakdown wasn't worse.

[Motonut]

Mind you I was told that a few days of riding would be ok.

 

Moral to this story is to not always listen to the good advice of others.

 

To anyone out there "listening" if YOU have noise coming from your rear end (your bikes rear end!) Stop riding it as soon as you can... you could end up as just another pizza on the highway.

 

Now you are faced with whether or not to heed this good advice.

[Paul Mihalka]

Well if end is good, all is good (Ende Gut, Alles Gut) - as far as not crashing. I recall 2+ years ago when my bike's rear drive was making the same expensive noises in Whistler/BC/Canada, my plan was riding it South across the border into Seattle. Our good friend Pilgrim told me that I should not risk it, and he picked me up with a trailer and took me to his home in Seattle. I'm glad I listened. I probably would have ended up like The Gorf

[smiller]

I'm shocked that your mechanic said it would be OK to ride it for "a few days" like that.

Me too. Coming from a professional that was an astonishingly inept bit of advice.

[Joe Frickin' Friday]

I don't buy into the fact that limited R and D dollars equals a poor design.

 

Limited R&D does not assure a bad product anymore than unlimited R&D assures a good product. But limited R&D does make a good design less likely.

[Bruce C]

I don't buy into the fact that limited R and D dollars equals a poor design.

 

Limited R&D does not assure a bad product anymore than unlimited R&D assures a good product. But limited R&D does make a good design less likely.

 

I think it's an excellent design. It is unfortunate that the read drive is over it's design limitations. Have you noticed the RT, RS, GT,or GS get any lighter over the years? Or have less horsepower? Of course not, but it's the same rear drive for the past 25 years. It is the same situation for clutch over the years. And I do fault BMW for supplying the consumer with what he wants(power and styling)and not repairing a known problem with the rear drive. It will be interesting to see how the new KS, KR and KGT rear drive fair.

Bruce C

[bvaughan]

So the local dealership looks the bike over and make some comments about the final drive. So now at 46K miles I have to replace a 1000$ part. I am utterly shocked. Is this common?

 

At this point, as soon as it's replaced this bike is going on the block. There is no question in my mind this time.

 

on my 1150 gs the final drive went south and was replaced on warranty at 35,500 miles. then when the input shaft bearing in the tranny went south at 46,000 miles, the shop said the final drive was bad too. i checked it; it was. kinda disappointing to have a final drive go bad in 11k.

 

by comparison, no probs knock wood knock woood knock wood with the rt after 70k.

 

the good news is that with the new ohlins and the wunderlich leg protectors the gs is an absolutely cush no buffet or bump ride.

[Global_Rider]

All of that requires testing, testing, and more testing to ensure the final product performs as intended.

 

 

And we're all there to do it for them.

 

When you have units going at vastly different mileages, you have a QA or assembly problem...or a lack-of-maintenance problem.

 

So the present generation of oilheads should have vastly reduced failure rates over the R11XX series, after all, why redesign something without the redesign being an improvement in reliability amongst other things. We'll see how the new generation rear drives do in a year or two, not that we're not reading about failures now.

 

Myself, I'm not worried. I change my lubes at least once a year and use Dow Corning Gear Guard M.

[Guest]

I think it's an excellent design. It is unfortunate that the read drive is over it's design limitations. Have you noticed the RT, RS, GT,or GS get any lighter over the years? Or have less horsepower? Of course not, but it's the same rear drive for the past 25 years. It is the same situation for clutch over the years. And I do fault BMW for supplying the consumer with what he wants(power and styling)and not repairing a known problem with the rear drive. It will be interesting to see how the new KS, KR and KGT rear drive fair.

Bruce C

 

I would argue with that. The design mates a deep groove ball bearing with a tapered roller bearing. By doing that, the weight carried by the hub acts like a trust load on the ball bearing. The new 1200 boxers don't do that any more.

 

FWIW, I've rebuilt 3 final drives and it is not hard. Rebuilding is 3-5x cheaper than replacement.

[The Gorf]

Here's what really gets me. My generation of rear drive is designed to have it's oil replaced. I have since learned that having made contact with a very reputable independant BMW mechanic here in Seattle. He says that for 250cc worth of oil, it's worth replacing every other oil change. According to him it's a good indicator that the drive is failing when the oil starts coming out dark or full of metal shavings (mine was both).

 

4 years of dealer visits, FOUR YEARS, and not once was my rear drive ever made mention of replacing fluids.

 

I digress, anyway what happens to the people with the new generation rear drive that is sealed? Does BMW really expect the system to last the life of the bike now? Common conversation on this board indicates that is apparently doesn't. Yet if oil conditions are a factor for determining drive failure, how are we suppose to know anything with a sealed system?

 

I think that I would much rather deal with a chain drive that I can visibly insepect every day and know exactly when it is going to have problems. Sure it means a more frequent chain change, but that beats what I went through anyday.

[nrp]

"I would argue with that. The design mates a deep groove ball bearing with a tapered roller bearing."

 

That is a very unusual combination to say the least, and could be prone to all sorts of assembly & preload mischief. Otherwise the radial and thrust load needs in a rear axle shouldn't be that serious. Is there any chance that gear debris is wrecking the bearings?

 

Regular axle oil changes are important as the antiwear additives in the oil will get used up in ordinary service.

[ShovelStrokeEd]

Almost all the rear drive failures have been bearing failures, not failures of the gears. Again, it is usually the large ball bearing that carries the wheel that dies. Reson is simple and has been stated, the bearing type (deep groove ball) is not appropriate for the application. Crown wheel and pinion thrust loads are the real culprit with added loading provided by the side thrust induced while cornering.

 

Quality oil, changed regularly, can mitigate the problem somwhat but it is always there. The drive is a unique design and can't really be compared to any other shaft drive or chain drive drive line. All other shaft driven bikes use a dual sided swing arm and a different bearing arrangement. Other single sided swing arm bikes (VFR, RC45) are chain driven and don't have the side thrust loads from the drive. They also use a ball bearing and taper bearing but, they are on opposite sides with the ball under the chain and the taper bearing supporting the wheel.

 

When BMW started with this design, it was adequate to the task. Motors made about 50HP and bike weights wsre in the 450 to 550 pound range. It's really our fault. We demanded more performance anc carrying capacity and we got it. Wet weights in the 650 to 850 lb range and HP up over 130 in the case of the K12LT. You will, if you watch things, see that the failure rate is much less on the naked or just sexy bikes like the R11xxR or 1100S. Reason being that these bikes are much lighter.

 

The new rear drive still uses a deep groove bearing supporting the wheel but uses a needle bearing at the drive side instead of the earlier taper roller bearing. This arrangement will tolerate thermal expansion better and therein may hold the key to increased longevity.

[Guest]

The new rear drive still uses a deep groove bearing supporting the wheel but uses a needle bearing at the drive side instead of the earlier taper roller bearing. This arrangement will tolerate thermal expansion better and therein may hold the key to increased longevity.

 

I agree with everything you say and want to emphasize the point of using the straight roller (needle) bearing over the taper roller bearing. The straight roller does not create thrust loads out of radial loads. Honda uses this configuration and just about everyone else. Endplay is controlled through the use of circlips in the shaft.

 

I'm typing one handed (sking accident) so I can't go into details but I have studied several drives and in all cases the crown bearing (deep groove ball bearing we've been talking about) will show signs of damage.

 

I believe all oilhead owners should learn how to remove the gear carrier from the final drive (the drive can stay on the bike) and inspect it for bad spots. Your ears are your best inspection tool for this. Spin the crown bearing in your hand and listen.

 

I cyrogenically heat treated the last crown bearing I replaced. Thats the only thing I can think of to do for this design.

[bmwscoot]

When BMW started with this design, it was adequate to the task. Motors made about 50HP and bike weights wsre in the 450 to 550 pound range. It's really our fault.....

 

Oh boy, Ed...I can disagree w/ ya on something!

 

I do not agree that it is our fault.

I agree with you that we demanded more power, and also more weight carry capability.

 

(a) I would think that an application engineer worth his salt, might have been able to foresee (engineering trait?) that the current (then) bearing loads/forces were not up to the limits of the heavier scoots, higher HP's.

 

(b) If that indeed happened, and the bean counters turned engineers at that point...and, well shame on BMW.

 

Either situation, it is their fault, not ours.

 

BMW made the decision (either bean counters or lack of R&D....both financial) to not provide the part necessary to accomplish the task at hand.

 

All of this said, it wasn't enough to keep me away from the roundel again. I knew all this stuff before I bought the new scoot.

 

 

[ShovelStrokeEd]

I couldn't find the tongue in cheek graemlin when I needed it.

 

Of course they took the easy/cheap way out and just continued the design past its original parameters. The K1200LT was the sign that they should have gone ahead and redesigned the thing. That it continues in the K series shows just how powerful the bean counters have become.

 

I'm thinking of a spline lube/inspection on my R1100S as I have another year to go with that bike. If/when I do so, I'll probably change the crown wheel bearing while I have it apart as a prophylaxis.

[bmwscoot]

Gotcha, Ed.

Good morning to ya.

 

If I would have been a little more awake this morning (pre-coffee) when reading your reply, I most likely would have caught the tongue-in-cheek tone contained there.

 

We are coming from the same position after all, concerning BMW design engineering.

 

Aaaaah....all is right with my little world again!

[nrp]

What rotates - the outer race or the inner race of the crown bearing? What are the approximate bearing dimensions? I wish I could see a cross section.

 

Usually a large diameter ball bearing has a radial and thrust load capacity far, far in excess of what any rear wheel and gear forces would be - unless it is a really small cross section.

 

THX

[ShovelStrokeEd]

It's actually pretty good sized, about a 305 as I recall. Problem is the bore is pretty big with respect to the OD, which makes for small balls. The bearing is also subject to spralling as the shock loads from the wheel go directly into the bearing races. The inner rotates with the outer race fixed (captured) by the housing.

 

As others have noted, it may well be an assembly issue with the preload on the taper bearing at the other end of the shaft, or with improper fits in either the housing OD or shaft OD. I examined the bearing on my '04's when it failed but it was too far gone, only about 1/2 the balls and both retainers shredded, to spot a root cause. The only real way to tell in these matters is inspection of the bearing at periodic intervls prior to failure. They usually will exhibit tell tale signs long before outright failure.

[Stan Walker]

I'm about to inspect mine at 69,500 miles, probably next weekend.

 

I've noticed a slight weeping at the crown seal but no play or roughness while turning the wheel. So it's time to take it apart and inspect. On hand I have a brand new crown gear bearing, the seal, and the cover 'O' ring.

 

I think BMW has changed the bearing. At least the part number from the MAX BMW site is no longer valid. The new number is 33121468899.

 

Stan

[Guest]

I'm about to inspect mine at 69,500 miles, probably next weekend.

 

I've noticed a slight weeping at the crown seal but no play or roughness while turning the wheel. So it's time to take it apart and inspect. On hand I have a brand new crown gear bearing, the seal, and the cover 'O' ring.

 

I think BMW has changed the bearing. At least the part number from the MAX BMW site is no longer valid. The new number is 33121468899.

 

Stan

 

The new bearing is french, the old bearing was german. the size is 85mm X 120mm X 18mm. if you do change the bearing, keep all the shims in the original location and you'll be good.

[Global_Rider]

The new bearing is French...

 

Oh no, that is where the Valeo starters are made.

[Stan Walker]

if you do change the bearing, keep all the shims in the original location and you'll be good.

 

I don't intend to change the bearing unless there is some indication of a problem once I get it apart. I ordered the bearing just in case........

 

And yes, I noticed that it is French, and with only 17 balls.

 

Stan

[nrp]

I see there is an assortment of shims listed. Is there a procedure that specifies the clearance or other setup of this bearing set (I should hope so)? I wouldn't assume the same shim pack if either bearing is replaced.

 

Maybe Fritz-at-the factory hasn't been getting them right either?

 

I looked at the load ratings of similar (FAG 6017 - but not exactly identical) bearings & they don't look like they should give trouble with the vertical load & speed spectrum that would be experienced in a motorcycle rear axle.

[Stan Walker]

Is there a procedure that specifies the clearance or other setup of this bearing set (I should hope so)? I wouldn't assume the same shim pack if either bearing is replaced.

 

Shim adjustments for tooth contact, backlash, and tapered bearing preload are all specified and the procedure for checking them detailed in the BMW shop manual.

 

Having said that, I believe that changing the deep-groove ball bearing is not likely to disturb anything in a final drive that is already correctly shimmed.

 

Stan

[Frank Cloud]

I don't buy into the fact that limited R and D dollars equals a poor design.

 

Limited R&D does not assure a bad product anymore than unlimited R&D assures a good product. But limited R&D does make a good design less likely.

 

Good point Mitch. Still, I think tooling is more the issue than R & D.

[Patallaire]

Changing the rear oil may help alleviate the problem but it is no guarantee. My rear bearing let go this summer with 49,000 on it, all oils have been changed every 5000 miles. Oil is cheap, the repair was not.

My philosophy about this is that these bike are machines, something is always inherently wrong with some part of a machine. Fix it and ride it.

When I owned Saabs{5} the dealer would tell me that different years had different problems, they all had problems, just different. It was like wine, different vintages create different results. I don't get upset over this stuff anymore, I guess you work through them, then the bike will be exactly as it should be, you will sell it and someone will get a completely debugged bike that will run forever, why not let that person be the person who put the money in it to solve all it's little issues. They all have issues, like us, some of them are different.