Clutch Spline Failure Analysis

[sweatmark]

Al - good tidbit, an interesting development... just hope the case doesn't get swept under the rug and "settled quietly".

[sweatmark]

Anyone have a photo of the flywheel/motor side of the drivetrain? Someone metioned the possibility (or lack thereof) for installing pilot bearing in typical automotive fashion. Just curious.

For the uninitiated (like me) who haven't pulled a transmission from a manual gearbox car, here's a cool vid clip focused on pilot bearing service:

http://www.rotaryengineillustrated.com/ ... -seal.html

Wanted: R1150R pilot bearings (and extended spline length transmission input shaft) for our bikes.

[NoRRmad]

I noted an interesting development on the spline failure issue. A 2002 R1150R owner on the MOA Oilhead forum had his splines fail at 55,000 miles. When BMWNA wouldn't help with the repair, he filed suit in small claims court. His intent is mainly to find out the scope of the problem through the discovery process. I wish him luck. Perhaps if enough owners sued BMW or there was a class action suit, them BMW would extend the warranty on the driveline.

In the meantime, however, BMW would probably not cover any non-warranty repairs on the splines because doing so would constitute an admission of fault, and could be brought up in court.

[aoldbmw]

call me old school. there isn't enough support for the FD and rear wheel torque. having a stylish flying rear wheel is no problem for chain drive. Put 85bhp onto a shaft that is supported by only one support bracket parrallel to the line of torque and you will get rotation --- at the face between the engine and the tranny. small alignment studs were fine for the older bikes with tube frames. Using the engine as part of the frame and FD to support the rear wheel weight and transmission torque just may be to much style for the engineering.

[ASQTec]

aoldbmw,

I had the same exact thought go through my mind right before I purchased my R back in '03.

While at the dealer, I noticed that the new R1150GS had a similar configuration. I figured that some of those GS's get pounded a lot more than our R's ever would, or should. If the clutch spine issue is more prevelant in the GS's, especially the ones that are used off-road, then I would consider the engine mounting configuration to be suspect. That's just my non-professional opinion.

[boxermania]

Gentlemen

One more time and to add fuel to the fire......most failures reported have been within the R259 family, or the commonly labeled "oilheads" of various displacements, however, it appears that the R models from 02' to 04’ as well as the RT's are the most afflicted models as the GS models seem to be watching from the sidelines.....so what is the common denominator?????

There are several issues relating to engineering design and or assembly that show as potential "initiators or contributors" to the incipient failure. Failures have been reported as early as 9K miles and as late as 55 K miles, although there is a significant population hovering around 30 K miles.

To me one of the most significant "engineering misses" is that unlike the input shaft of automobile transmissions that "pilot" onto the rear of the crankshaft to perpetuate CL alignment, our bikes tranny input shaft does not pilot onto the crankshaft, since the shaft is hollow to carry the rod that activates the diaphragm clutch. In essence the clutch disc is the bridge of the engine torque transfer to the gearbox and this is taking place on a cantilevered arm.....whose lateral movement as a result of the rotational force is contained only by the tranny input shaft roller bearing.......and there is more.....but that is enough for now......I need nourishment as I'm weak and tired......

[Jammess]

call me old school. there isn't enough support for the FD and rear wheel torque. having a stylish flying rear wheel is no problem for chain drive. Put 85bhp onto a shaft that is supported by only one support bracket parrallel to the line of torque and you will get rotation --- at the face between the engine and the tranny. small alignment studs were fine for the older bikes with tube frames. Using the engine as part of the frame and FD to support the rear wheel weight and transmission torque just may be to much style for the engineering.

I tend to agree with you. Seems to me clutch spline failures became an issue with the introduction of the K bikes when the engine became a stressed part of the frame. In subsequent years power increased and clutch spline failure rates seemed to increase as well. I have a hard time believing that if the problem were caused by engine/trans alignment that BMW would not have solved the problem years ago. But if the basic design which uses the engine as a stressed member were the problem how could BMW provide a fix short of a complete redesign?

I have an '041150RT with 34K miles and this business of clutch/spline failure and the cost to repair just flat makes me nervous. If I had been aware of the problem I would never have purchased an oilhead in the first place and I sure as hell would never buy another new BMW now. The Yamaha FJR1300 is really looking good.
I am thinking about separating the trans from the engine for a spline lube and inspection. Thing that bothers me is do I really want to know what the condition of the splines is? Or do I want to just sell the bike and take my business elsewhere? Oh, and then there is the final drive problems that seem to plague the hexhead machines. This is just depressing.

[Beemeridian]

33

[boxermania]

Beemeridian

I don't know how to respond to your first question as mine was an 02' and although I moded the bie and took it appart a number of times, never had any failures, in 17 k miles, as experienced by other owners. On the other hand, I didn't pop wheelies or stopies, but being that I'm marketing size you could say that the bike was ridden mostly 2 up. In regards to operation, I definitely enjoyed and tached the bike in every gear as the opportunity arose.....

On the second question, your comment has merit, unfortunately, I haven't seen one in the flesh to verify any type of wear pattern. I do know that the rod, inside the tranny input shaft has quite a bit of clearnce in it's bore.

Most recently I hooked up with Lobo 1625, out of the Fort Worth area and we might be able to take the current research one step further as we are looking for a donor bike to try to validate what the failure paterns seem to point at.....just sent him a set of failed parts.......

[sweatmark]

Haven't the boxers had this same type of clutch actuation since the airhead days?

http://www.largiader.com/articles/throwout/

Why can't the clutch pushrod somehow mate with the crankshaft end to provide pilot bearing function, a couple of bearings thrown in for good measure?

[awagnon]

I am thinking about separating the trans from the engine for a spline lube and inspection. Thing that bothers me is do I really want to know what the condition of the splines is? Or do I want to just sell the bike and take my business elsewhere?

That's what happened to me. I took my '02 RT (43,000 miles) apart to lube the splines and discovered they were nearly gone. I was tempted to put it back together and trade it in knowing the splines would probably fail in the next 5,000 miles. I decided I couldn't screw someone else with my problem. Even if I traded in to a dealer, some poor sap would end up with my POS. I ended up fixing it. I will pull the tranny again next winter after 15,000 - 20,000 miles and see if the new splines are holding up. If they aren't, then the bike goes. I'm thinking seriously about selling my '04 1150R before I have to deal with this again on another bike.

[nonskid]

This is a scarry situation! I have 15,500 miles on my 02 R and I sure hope I don't have to ever deal with this problem. If this isn't a manufacturers defect then what is?? I did print a copy of the aftermarket shaft co. just in case. I wonder if anyone has ever been hert or injured because of this happening.

[Lobo1625]

Some more info regarding Clutch Splines and possible cause for failure. I had recently received a failed clutch disk and splined input shaft from Boxermania and helped Obaid put a new clutch in his '02 R The part numbers on the clutch disks that had failed were the same (21.21-2333262) The box that I received the failed disk in was 21 21 7 670 454 and matched the replacement disk we put in Obaid's bike. Seems that sometime during the life of these bikes, BMW replaced the clutch with a different P/N. As for differences between the two part numbers, there were none visually.

I had the failed input shaft and older failed disk checked for hardness yesterday. The results were disappointing at the least. The shaft measured a 55 on the Rockwell Hardness C scale, indicating that it had indeed been heat treaded and hardened as we all expected. The hub on the clutch disk measured a mere 22 RHC, quite soft in comparison. This indicates that there's practically no heat treating on the clutch disk at all. It is good that the clutch disk is softer than the shaft so it is the wear part, but the lack of hardening at all is negligent on BMW's part.

I'm curious if anyone has a replacement or possibly 'late model' clutch disk (P/N 21 21 7 670 454) that has failed that could be tested for hardness. It could be possible BMW made a switch in the hub at some point but obviously didn't make it public. It's also quite possible that the difference in part numbers is something as simple as the friction material used on the disk...

I'm doing some research and talking with a few clutch manufacturers to see about creating a reliable aftermarket clutch disk to replace the OEM BMW part. I see this as a great fix requiring only a few hours to change. I'm also asking them to make the disk hub longer to increase engagement to the shaft towards the transmission. I believe these few changes would result in a much more reliable part, and would quell many fears about recurring spline failures.

I don't have much more information at this time, but will keep this thread updated with info I find, or create a new thread gaging interest in an aftermarket disk. The more we people we have interested the more likely they are going to be to produce parts at a reasonable price. If anyone out there has a late model disk that they could have hardness tested or possibly send to me for testing, that would help considerably. Also if anyone has a clutch disk with a part number different than those I've mentioned, that would be good information to have cataloged.

[Buckster]

Thanks for the update Lobo. I know I as well as many others are interested in what you find. Thanks for taking your time to do this research. It is appreciated!

[shoei]

November 2003 1150RT 33000 miles splines just gone. £1300 repair bill coming my way!!!!

[boxermania]

Once again not to cause a panic, but for the naysayers....there are a significant number of failures out there and mind you these are not insignificant failures.

Review of those that I'm aware of indicates that the majority of the failures occur around 30 K miles, with some as early as 10 k miles and others as late as 50 K miles.

I'm waiting for Lobo to tear his down, I think he has 12K miles.....I'll have to see if I get to have Boxer, tear his down, as he has 73 K miles and will probably be in need of a clutch soon.....that would be a nice data point, both from the splines and the clutch wear standpoint.

[busithoth]

Okay, I'm officially a little freaked out.

I went to look at a 2002 R1150R with 4500 miles on it.
It's in mint shape, and I almost left a deposit, but wanted to do more research on the bike first.

Since then I've read all the spline threads on these forums (and elsewhere) and I now feel really hesitant to buy the bike.
There's not enough miles to know whether this one's got a problem or not, and I cannot tell how common this failure is.

Is there any way to find out?

my first thought was that IF it did fail, I'd replace the spline with that $1000 aftermarket spline, but notice there's no feedback on how that works for people. And from what I understand, that'd bring the repair bill up to around $3,000 to try it out. This seems like way too much money to experiment with an already premium bike. I plan on riding a LOT this year, and expect that I'd be hitting the mileage where it begins to fail by the end of it.

This thing is out of warranty, and I'd be the second owner, so BMW would have to problem denying it's their design at fault.

It's been mentioned how many people wouldn't buy another BMW because of this problem, and I'm wondering if I should spare myself the same revelation (and money). It's really annoying, because I'm itching to buy, and it's down to a Ducati ST2 and this 1150R. The BMW is a fair bit more, which would be justified if I weren't so scared about losing the clutch in the badlands...

[awagnon]

Okay, I'm officially a little freaked out.

Hi, Busithoth. You'll get lots of opinions, but most will probably say get the bike you like most, makes you smile the most and don't worry about the spines. Mine went out on my RT, but I don't worry about the 1150R. The odds are still small that any single BMW will suffer a spline failure. Any bike from any manufacturer can have mechanical problems. The r-bike sounds like a nice bike. If you like it, get it and ride it. If you worry, then this winter, do a spline lube and take a look at the condition of the splines for peace of mind. It really isn't a major job. Just my $ .02 worth.

[busithoth]

I suppose it is really gnit-picking at this point.
I test rode the Ducati ST2 today, and didn't like it much at all.
I'm just not for that forward position (and I understand that's not even a sport bike, officially).
It ran great, though. Responsive as hell, front brakes that could toss you over EASY.

Altogether different direction than what I'm looking for, though.

Now I'll just need to get used to moving that 1150R frame through the Brooklyn streets.
Very different from my '83 Honda CB1000 Custom...

[sweatmark]

Today's spline failure tidbit:

Talked off the record with a service guy at regional BMW shop, asked him point blank about number of spline failures seen at the store. Answer was "Hardly any, besides the police bikes which get ridden pretty hard. They have lots of input shaft and clutch replacements."

Anyone have contacts at BMW shops that service Authority bikes around the country? Would be interesting to get info about service histories for R1150RT-P "motors" exposed to (assumed) tough duty.