My clutch and input splines (photos)

[RickP]

Four weeks ago today, I lost forward motion while stopped at a traffic light. My dealer just finally got to it late this week so I visited my missing friend today.

 

04 RT (purchased 10/04) 12-13K miles

 

This is why doctors don't allow visitors in the operating room.

 

old clutch plate & trans

 

I'm receiving new trans and complete clutch ass'y though

 

Since it was such a nice day today, and this one had the keys in it, I took it for a ride until dark and am holding it hostage in MY garage.

 

-RickP.

[smiller]

Man, I really wonder why this problem affects some bikes at relatively low mileage and others not at all. Been discussed to death here of course, and it's kind of frustrating that (due to the high number of occurrences of this problem) BMW must know the precise reason for this by now, but won't breathe a word as to why, or even confirm the problem.

 

Anyway, glad you're under warranty..!

[GaryIF]

The first photo sure looks to be at Bob's BMW in Jessup. Yes?

[ignatz]

Is it that much labor to replace the input shaft? Or is it the transmission housing causing the problem? I remember working at an MG dealer where a customers car had a trans leak that turned out to be a casting problem where the oil was leaking through the housing. They made me swap everything over to a new housing. Don't they trust mechanics working on this stuff?

[Martyn]

That looks distressingly familiar; my R1150RT went at 20,170 miles, with no warning whatsoever. Cost GB £766, which luckily BMW later refunded. The new clutch plate & shaft look identical, but short of a forensic style exam, no way of telling if in fact the specification has been uprated, or whether the originals failed to meet their specified standard.

My dealer has had 4 such failures to my certain knowledge; my 1150R has 16,000 miles on the clock which poses a dilemma. Do I get the plate changed "just in case" or ride on & see what, if anything, happens?

[RTCHIEF]

Can't see the clutch splines that well in the picture, but it appears that the outer edge of the input shaft splines failed. Could it be that the splines were not making full contact?

[RickP]

Gary - Yes it's Bob's.

 

Clutch disc spline is much worse than picture shows and not worn even. I'd say the circle one-third destroyed, one-third very worn, and one-third worn.

 

This bike also has an extra varible in that it received a complete factory engine (including clutch!) at 1068 mi.

 

Looking back, I did have warnings: balky down-shifting at slow speeds frequently when coming to a stop. And the last two or three weeks before failure--stinky smell and heat on my right calf when stopped.

 

The bike had its 12K TWO DAYS before failure. They specically checked the clutch - at least it was on the RO. You guys are getting me started now. I think I'm keeping this ST all winter for "mental anguish".

 

(*0@#131$@$!!!!!

 

-RickP

[twilmotte]

Oh, oh. Your "stinky smell" symptom concerns me. I've smelled "a stinky smell" from my '04 RT occasionally and thought it might be clutch slipping/burning (although it didn't really feel like it was slipping). Any others out there whiffing a "stinky smell" from their RT? I think I'm going to lose some sleep over this thread, dang it.

[RickP]

Your RT clutch will definitely have an "organic" stinky smell when "abused", like starting on steep hill. But it goes away quickly. I'm talking about stopping and parking the bike an going "what's that smell?"

[twilmotte]

Whew! I've the "goes away quickly" stinky smell. (At least for now.) Thanks for getting back to me.

[nrp]

Could it simply be a sloppy or incomplete lube job on the spline on assembly? Unlike gears, splines won't naturally distribute grease around the wearing surfaces. Both male and female elements should be completely dried of any solvent and then lubed all around with the proper stuff.

 

What is everyone using now days?

 

Another key might be the Rockwell (Rc) hardness of the clutch spider. Is it softer on one side (the totally shot side) than on the opposite? A skilled machinist can get an idea of the relative hardness with just a file.

[Mr. Frank]

On the older K bikes which had lots of problems with the rear drives wearing, Honda Moly 60 Paste was a good choice.

[RFW]

Oh, oh. Your "stinky smell" symptom concerns me. I've smelled "a stinky smell" from my '04 RT occasionally and thought it might be clutch slipping/burning (although it didn't really feel like it was slipping). Any others out there whiffing a "stinky smell" from their RT? I think I'm going to lose some sleep over this thread, dang it.

 

I don't see any connection between clutch slipping and spline damage. The clutch can slip all it wants, but that does not affect the loading on the splines, and should not affect the splines in any way.

 

Bob.

[mbohn]

I hope you have better luck than me. My bike has a similar problem that BMW has tried to fix 7 times over pretty much the entire life of the bike. The input splines are destroyed in as little as a few hundred miles of riding. Once it destroyed the clutch disk.

 

In all but one case BMW fixed it but under duress. The last case they replaced the gearbox and the symptoms returned after a few months. I had to disassemble the bike 2 years ago and diagnose the problem for them: The engine and gearbox are not aligned and the bike was assembled at the factory with one of two engine-gearbox alignment pins missing!

 

It is pretty obvious to me at this point that BMW is not capable of solving this problem once and for all. Yesterday I started yet another disassembly (looks just like your photo) and I should have the gearbox off the bike later this morning.

 

If your bike gets fixed let us know if they have a true diagnosis and also if it continues to work for a long time. As I said before mine failed in as little as a few hundred miles and in as much as 30000 miles.

[Dewayne Harkov]

I would guess the trans splines have a bad heat treat leaving them too soft to hold up. The clutch hub should NOT be harder than the trans shaft. The clutch hub should wear first as it's a replaceable item. BMW should stand behind an obvious manufacturing defect. Yeah right! Everyone should write a letter to the National Highway Safety Council or whoever that logs complaints for recalls and complain. It just may get done.

[Martyn]

I would guess the trans splines have a bad heat treat leaving them too soft to hold up. The clutch hub should NOT be harder than the trans shaft. The clutch hub should wear first as it's a replaceable item. BMW should stand behind an obvious manufacturing defect. Yeah right! Everyone should write a letter to the National Highway Safety Council or whoever that logs complaints for recalls and complain. It just may get done.

When my shaft/clutch went, I thought it a bit of a clue that my dealer had all the parts, including the input shaft, "on the shelf" - I asked if they had similar spares in stock for K-Series or air-heads, to which the reply was "no"

[270]

These stories always make be GULP!! I just turned 27K on my '04 (purchased 7/31/04). I've had no issues save for the clock on the RID.

 

More than likely, I WILL be performing a spline inspection/lube at ~50K as I always did with older K-bikes. I never got an un-pleasant surprise when opening those things up and it made me feel very confidant until the next scheduled lube interval. However, these things eating themselves at 13-15K are just wild. Thats simply no time at all.

 

Here is a waste of bandwidth..."Hey BMW...if you want to be the leaders in the 'boutique' motorcycle market by marketing legendary reliability, why not put your money where your mouth is; 100K power train limited warranty?" I know, I know...3/36 is one of the best in the industry, but BMW riders as a whole easily outride the warranty by milage over time.

 

That my friends, is a ridiculous failure, regardless of whether or not it's covered. And it comes on the heals of a motor transplant as well!!

 

The slowly evolving BMW death spiral is evident IMH(humble)O.

[Bakaboy]

I know, I know...3/36 is one of the best in the industry, but BMW riders as a whole easily outride the warranty by milage over time.

 

 

Not that I'm complaining

 

And you may already know this, but why is the Canadian Warranty 3 Years, Unlimited Distance?

[Eckhard Grohe]

Becuase the shorter riding season prevents all but a few from riding more than 36 k miles, kilometers or leagues anyway.

 

Global warming may change that though.

[RickP]

To be fair the motor didn't fail, I put a rock through the bottom of the engine on the BRP. The long sad story is here - http://bmwsporttouring.com/ubbthreads/sh...true#Post418520

[mbohn]

I would guess the trans splines have a bad heat treat leaving them too soft to hold up. The clutch hub should NOT be harder than the trans shaft. The clutch hub should wear first as it's a replaceable item. BMW should stand behind an obvious manufacturing defect. Yeah right! Everyone should write a letter to the National Highway Safety Council or whoever that logs complaints for recalls and complain. It just may get done.

 

The clutch splines should fail before the input shaft splines but they don't. I have a photo of one of my input shafts that were replaced: the splines look terrible but not as bad as those in the photo in this thread. I've just removed my gearbox yesterday and can see that the splines are only slightly worn, not nearly as bad as the preceeding shaft. But it still creates shifting problems.

[mbohn]

I've modified my gearbox cover and engine/gearbox alignment pins to bring the crankshaft and gearbox input shaft into alignment. When I started they were off by about 0.005" and now they are less than 0.002". Tolerance limit for DIN 5480 splines is 0.003". I'm presently re-assembling the bike and will report back on results.

 

Seeing how far out my alignment was makes me suspect that this is why some bikes have early spline problems. Mine started at 14000 miles and has persisted to 70000 after 7 repairs. (Yes, I could probably write a book on this saga). If mine was off by 0.005" it is hard to believe that is the only bike ever built that was not in spec.

[nrp]

How were you able to measure the alignment of the two shaft axes, since it is a blind assembly? I've been trying to figure out a way.

[mbohn]

How were you able to measure the alignment of the two shaft axes, since it is a blind assembly? I've been trying to figure out a way.

I built a tool that bolts to the end of the crankshaft using the flywheel bolt holes. The tool protrudes through the gearbox front cover (which has been removed from the gearbox). I then use a telescoping gauge between the tool and the input shaft front bearing seat to measure the radial distance from the tool to the bearing seat. I make this measurement at four locations roughly 10, 2, 5, 8 oclock. I'll try to attach a photo of the tool. The red radial line shows one such gaps I measure.

[nrp]

Very good. I assume from the penned arrow on the dummy crankshaft extension that you rotate the crank to the measured position each time. That way you would eliminate any error in your fixture.

 

Congratulations if that's any comfort. I think you have found the smoking gun. We now need to find the runnout of any similar failures. Too bad the transmission has to be taken apart to make the measurement.

 

Now raise hell and put blocks under it.

[mbohn]

Very good. I assume from the penned arrow on the dummy crankshaft extension that you rotate the crank to the measured position each time. That way you would eliminate any error in your fixture.

 

Congratulations if that's any comfort. I think you have found the smoking gun. We now need to find the runnout of any similar failures. Too bad the transmission has to be taken apart to make the measurement.

 

Now raise hell and put blocks under it.

You are correct. I measure the runout of the tool with a dial indicator by rotating the engine through 90 degrees at a time . I then take those measurements to correct the actual alignment measurements. The runout was pretty small compared to the misalignment I was trying to measure, about 0.00075" or less so I felt pretty good about that.

[chrisx]

how did you verify that the tool was centered with respect to the crank? am i missing something?? this is an interesting problem. my 04rt has barely 1k miles. i'm thinking a verification may be in order, obviously some bikes were made on monday after oktoberfest. i wonder if they had to do a "piece match" at assembly time? that can produce error as well.

 

if the locating pins are not 180 degr apart it may be possible to measure offset via geometry. or a flat plate wie a bore int middle that uses the locating pins? i could probably get a pro job done cheap for that if anyone has ideas. bro has a prototype shop. i wonder if a set of dimensions is available for those two castings. then the error could be calc'd from center/or shaft far side perp to locater pin bores. i suppose that a tool could be bolted or even clamped to determine individual shaft to mounting surface square although it appears the primary culpirt is trans to engine, and the fix irrespective of cause. be nice to find a way to measure it without tearing it down so far.

 

 

Interesting thread. I wonder if there is any data in re to assembly runs that were problematic. i have no problem "blueprinting it", which seems to be the crux. This is my first motorcycle, ( and that's why it only has 1k, i'm in no hurry to get in trouble. ) it is smaller than my car which has had every single part hacked on. can't be that hard, at least i don't need a 1/2 ton hoist. perhaps there is a market for a rehardened shaft even? any scuttlebut on whether the material itself is in question?

 

 

sorry to ramble. this is a great board.

[mountainred]

Dewayne has a good point on shaft hardness. there is a simple test/tool to check the rockwell hardness. the next one who has to do a teardown or already has one apart, should do this test. If I am the next unfortunate one, and I hope not since I just put it together, I will compare it with the other (output) shafts and components and post the results.

[nrp]

A simple way to check Rockwell hardness is to try to cut it with a file. If it is over about 58 Rc, a file won't touch it. The clutch internal spline may be expected to be a little softer.

 

The spline failure problem is probably the result of the spline dragging the clutch disk around the flywheel during all engaged operation. This can only occur if the shafts are not in line. Failure is a result of the considerable rotating sideload (like maybe 1000 lbs or so) being applied to the spline. This would also explain the scored or burned flywheel faces.

 

If the splines are near failure, the clutch disc will jam or wedge on the remaining spline teeth such that only half of the clutch will disengage. The other (front side) of the clutch will still keep pressing on the flywheel - hence the difficulty shifting.

 

By the time you have a hard shifting symptom, the splines are probably very near failure.

 

This is all making more sense now.

[Spike]

Rick, I think its time you looked at that ST3 you were thinking about. I know where you can get a great one.