02 RT grind grind grunch.... then coast off the highway

[dirtrider]

Another thought - There will be plenty of magnetic dust inside the BELL housing of any worn spline system.

 

Based on my 2000 R1100RT though, a truly pristine spline is very clean and not grundged up with black crud like all these failed photos show.

 

Afternoon NRP

 

 

Yes, that is pretty visible in most failure photos, but is it appearing early enough in the failure to use a gauge?

 

Might only be showing that much metallic after total strip out & spline annihilation.

 

[dirtrider]

DR - ypu've been holding out on us if you have a Bridgeport with digital readout.........

 

Note though that to get the true axis of the transmission, you will have to dial indicate on both the input bearing housing and the rear bearing housing ID before looking at the alignment pin holes. Either that or make a mandrel of sorts.

 

I would expect that since this casting is done in a Cartesian coordinate (X and Y) boring machine of some sort, that the location of the alignment pins with respect to the transmission axis would be an even millimeter metric measurement, rather than angle based.

 

But even if we recreate the correct alignment pin measurements, for field fixes wouldn't it be easier to just sweep that transmission bore with respect to the crankshaft to eliminate any fixture errors?

 

I think if we made offset alignment pins, they could be marked with the high side for any bike that has been indicator swept.

 

Of course if there was a way to do it without disassembling the transmission that would be much better. A split thin wall sleeve slipped over the input shaft splines would allow allow a similar measurement, but it would require the clutch disk to be removed. Of course it usually has to come out anyways.

 

Just thinkin!.....

 

Afternoon NRP

 

Yes, if I wanted to do it to the n'th degree with angles, radial offset, probably even measure the input shaft run out. Then measure engine to pins as well as crank movement & rear of block to crankshaft angle. (basically how I would do it at at work for full root cause analysis).

 

With the JUST the front housing from a KNOWN GOOD long life spline trans & a front housing from a early failed spline trans the idea is to JUST measure IF there is blatant difference between a known good trans & known bad trans front housing.

 

If the front housings are real close then we would have to look elsewhere for the root cause.

 

But, on the other hand IF there is a clearly shown difference between a failed trans front housing & a non failed housing there IS a chance we could use the coordinates of the good housing to set up the front housings on the mill then machine out the alignment pin holes to an over size (on correct centers of course) then use stepped alignment pins to correct trans to engine centering on existing bad front housings. (ie, ship a bad housing & receive it back correctly drilled & stepped pins to align to engine)

 

Of course sweeping the existing housing & centering to existing engine is probably the most fool proof but most home mechanics just don't have the measuring tools or expertise to pull that off)

 

 

 

 

[nrp]

Yes, if I wanted to do it to the n'th degree with angles, radial offset, probably even measure the input shaft run out. Then measure engine to pins as well as crank movement & rear of block to crankshaft angle. (basically how I would do it at at work for full root cause analysis).

 

With the JUST the front housing from a KNOWN GOOD long life spline trans & a front housing from a early failed spline trans the idea is to JUST measure IF there is blatant difference between a known good trans & known bad trans front housing.

 

If the front housings are real close then we would have to look elsewhere for the root cause.

 

But, on the other hand IF there is a clearly shown difference between a failed trans front housing & a non failed housing there IS a chance we could use the coordinates of the good housing to set up the front housings on the mill then machine out the alignment pin holes to an over size (on correct centers of course) then use stepped alignment pins to correct trans to engine centering on existing bad front housings. (ie, ship a bad housing & receive it back correctly drilled & stepped pins to align to engine)

 

Of course sweeping the existing housing & centering to existing engine is probably the most fool proof but most home mechanics just don't have the measuring tools or expertise to pull that off)

I now see what you are thinking. It would also have the advantage that it would cancel out as much of any complementary main bearing wear too.

[roger 04 rt]

It seems every year that the clutch spline threads start up in the winter/spring. Here is a recent post on the MOA board, from another source, which echoes Anton Largiader's view on clutch pack replacement.

 

I have seen this same wear pattern on a friend's 96RT. It turned out to be a warped rear pressure plate that held the clutch disc at an angle. Every time the clutch locked up it was at a new angle that produced a new wear area on the hub and input shaft. Unfortunately it took a replacement clutch disk and input shaft that only lasted 12K miles before we found the problem. Learned to replace ALL the clutch parts when doing a service.

[dirtrider]

Afternoon Roger

 

I guess I would have to see it go well past that 12K with the new parts to put much stock in that being the ORIGINAL root cause.

 

He didn't say how far it went on the first failure (if significantly over 12K then they probably bent the clutch parts at re-assembly).

 

[roger 04 rt]

Hi DR, I've asked the OP of those comments your questions.

 

Since the clutch hub is offset from the front/back centerline, it seems to me that a warped clutch pak would create an alignment offset.

[dirtrider]

Hi DR, I've asked the OP of those comments your questions.

 

Since the clutch hub is offset from the front/back centerline, it seems to me that a warped clutch pak would create an alignment offset.

 

Morning Roger

 

Possibly but you would then also think it would have one heck of a one-per-rev vibration.

 

The thing to keep in mind here is we are dealing with a 96 1100 5 speed. Very few spline failures in those as built so this is basically an outlier. Like something damaged at assembly, or damaged from some type of service, or something worn.

 

What is the vehicle service history? Are they first owner with total bike history? Was this bike updated at one time with the BMW anti-rattle tighter clutch disk hub? Was bike split at one time for oil leak or trans repairs?

 

No mention of checking/verifying trans to engine alignment, or if something was bent, or even original miles to first failure.

 

We are dealing with a sample of (1) here with no miles to failures furnished on a bike/engine/trans not normally known for spline failures.

 

Maybe the full spline engagement of the 1100 5 speed killed the splines.

 

Sounds like a lot of guessing on clutch pack being root cause with no data to verify other possibilities.

 

[roger 04 rt]

Hi DR,

True, this is an 1100. But I posted it because if a deformed clutch pack can cause the lower-wearing 1100 to wear out, then the same seems likely to hold true for the 1150.

 

I found it interesting that the OP of that data point knew to comment that each disengagement/engagement cycle would change the pressure point. And of course Anton Largiader, who repairs a lot of transmissions suggests the same failure mechanism.

 

This is not to say that the primary cause isn't alignment, rather to offer another mechanism by which that misalignment could occur.

 

You mention vibration but I don't know what the warp to vibration function would be. For a 0.010" offset caused by clutch pack warpage you would still have pretty good radial distribution of the mass, so perhaps not much vibration at all.

 

If and when I hear from the OP I'll add it to the thread.

[dirtrider]

Afternoon Roger

 

If it's bent then it's OD is not true to center any more so that is a LOT of mass running @ 5000 rpms slightly askew.

[dirtrider]

Afternoon Roger

 

Common sense kind of tells us that IF the clutch disk was wobbling & causing the wear then it would not wear the splines on ONLY the rear, as you would think the front of splines would show the opposite wear due to the disk wobble switching planes with rotation.

 

To me it looks like these splines were always loaded with the same misalignment angle. (not switching back & forth)

 

 

[roger 04 rt]

Evening DR,

If common sense could be easily applied to this problem we'd all be writing about something else. Part of the problem here is imagining how the spline and hub interact in the presence of centerline offsets (CO) and angular errors (AE).

 

To some degree CO and AE are related. Create a CO and the hub has an angular force in the direction of the offset. Bend the clutch components, and you shift the centerline. Create either error and fewer gear teeth carry the load (according to some good papers I've read). With either error you introduce an orbital surface contact motion.

 

The wear is on one side of the teeth (mainly) because with a CO, the contacting teeth are the 1-3 teeth at the top of the offset. For example if the input shaft is high relative to the hub, the teeth at the top make contact, but rock up and down as they engage and disengage through the contact area. Again, according to a paper I read.

 

This relative up/down rocking of the tooth as it sweeps through the area where the teeth carry force in a CO situation get exacerbated with a shorter insertion, it seems to me.

 

I've also read that with a CO, as the joint wears, the number of teeth carrying the load is reduced.

 

To me, the geometry and forces are mind boggling. And so much wear caused by something greater than 0.010" of centerline offset!

[dirtrider]

Morning Roger

 

Well common sense tells me the ones I have repaired have stayed repaired so what I did has worked well.

 

Talk & speculation is one thing but until people start measuring these things it is just that.

 

[roger 04 rt]

Morning Roger

 

...

 

Talk & speculation is one thing but until people start measuring these things it is just that.

 

Agree 1000%. We need to add flywheel, clutch disk and pressure plate to the list.

[roger 04 rt]

Assuming that the clutch hub projects about 1/2" outward from the plane of the clutch plate. I think that each 1 degree of clutch pack error with respect to the plane it runs in should create about 0.008" centerline shift between hub and input shaft. Could it be warped as much as 2-3 degrees?

RB

[Redman]

As I said before, I was reading aobut this spline wear-failure after buying the bike... and before I went out there to ride it.

So I knew some about it.

 

And I do appreciate all this further detail analysis / discussions.

 

Yah, I can see how angular missalignment can cause the wear, and how raidial offset-allignemnt can cause about the same wear when consider the clutch plate flexing.

And in all this discussion, noone has ever said that BMW ever made any statement about this as being a common problem.

 

As far as how many and how common.... havent seen any thing to definite other than some folks said that for a few years there some dealers were doing half dozen to a dozen of them a year.

(someone must know based on sales of the replacement input shaft and such)

 

I am going on the idea that the missalignment is related to the transmission housing/ mounting. More likley a machining/productiuon problem than a design problem (hense why some worse than others, and many are okay). And made worse by the design problem of the not full engagement of the hub/spline. And made worse by surging, and made worse if rider luggs it in too high a gear (too low rpm).

 

 

 

.

 

.

 

 

 

.......

So I guess these BMWs are expensive to own.

Lets see, how many thousand dollars, divide by how many days I have ridden it, that works out to about a $1000 a day.

.

.

 

Update.

Repairs are complete (used clutch and rebuilt xmission from bike that had spline failure at ~80K and new clutch and rebuilt the transmission, then engine failure the next year).

 

And completed the maintenance items it was behind on (valve adjust, TB clean/sync, brake flush, new clutch cylinder that was leaking, new alt belt, in tank gas tubes).

 

Add all that up, and divide by the days I had to ride it, and at present that works to to about $1775 a day.

 

If add all that up, and subtract off what I think I could sell it for, now that is up-to-date on maintentance, and divide by the days I had it to ride, that works out to about $550 a day.

guess I need to ride it more days to bring down that amount, eh.

[mneblett]

Glad to hear you are back underway. I hope your enjoyment of the RT riding experience helps the "cost per day" decrease even faster!

[AndyS]

Hi Redman, I hope you get a good bunch of riding in now. Let us know.

[Froggy]

Well where's the spline list cause I need to add my name. 02RT with 32900 miles. Took a yield turn in second and gassed it...zzzzing, you have got to be kidding me.

[dirtrider]

Well where's the spline list cause I need to add my name. 02RT with 32900 miles. Took a yield turn in second and gassed it...zzzzing, you have got to be kidding me.

 

Clicky Here

[Redman]

Glad to hear you are back underway. I hope your enjoyment of the RT riding experience helps the "cost per day" decrease even faster!

 

Hi Redman, I hope you get a good bunch of riding in now. Let us know.

 

Yep, is back together... want to get on it, hit the starter, feel it shudder sideways, and go for ride... Japatul, Sunset Highway, Palomar... but the bike is 2250 miles away.

 

.

[Redman]

Well where's the spline list cause I need to add my name. 02RT with 32900 miles. Took a yield turn in second and gassed it...zzzzing, you have got to be kidding me.

 

Ah, man, Froggy ! !

 

And, let me guess, you knew what it was right away. You had been in fear of this for some time. At some point you got a BMW with the idea of them being known for reliability, and then find out about the 02 RTs three somewhat common problems, and then ride in fear.

 

Are you familiar with the options for the spline repair ...?

I can tell you what a BMW dealer is going to say. I can tell you what some folks on here are going to say. And can tell you what some other folks are gonna say, and I can tell you what yet some other folks are gonna say.

 

Were you joking about "signing up for the list" ? ... and then find out there IS a list...? har har har

 

Dave

[Froggy]

Have already had the abs problem last year with a close call with no power to the brakes. I ripped out the abs system and feel much safer...and now this.

You have read my mind about the reasons to buy my 1st BMW.

I will be removing the trans.as a unit with the drive shafts attached and have a look inside.

[eddd]

 

 

You might want to reconsider this approach. Removing everything as a unit has its own difficulties, but that's not the big issue, putting things back together is much more difficult.

 

Taking things down to the components doesn't take much more time and may save you some frustration and time when it comes to reinstall. Keep in mind that if you run into difficulties trying to get things back together as a unit and then decide to taking everything apart you'll find that it would have been much easier to do that when everything was still on the bike.

 

Just some food for thought.

[Redman]

Have already had the abs problem last year with a close call with no power to the brakes. I ripped out the abs system and feel much safer...and now this......

... and if/when have the surging problem, then will have the trifecta of 02 1150 problem.

 

 

 

....

You have read my mind about the reasons to buy my 1st BMW.....

Just assuming my situation was same as yours.

 

 

 

...

....

I will be removing the trans.as a unit with the drive shafts attached and have a look inside.

 

ONly comment I can make about order of dissasembly and reassembly is to tell you my experince, and that is it was dissasembled, I buy salvage used clutch and xmission, I approve $700 charge on credit card, it was reassembled, I approve a big charge on credit card.

(bike being 2250 miles from home, and where I want to ride it).

 

 

I can tell you what are probably going to find.

WIll find xmission input shaft splines worn some, and wear pattern not parallel to the splines.

Will find clutch hub splines worn to the point of catastrophic failure and are chunks of them scattered around in there. I say this from my expereince, and what have seen documented many times (since I got my 1st BMW in November... and started learning about this).

 

And to further yammer on:

Prevailing opinion/thereorys is the wear due to missalignment. Type of misalignment ... and specific cause of the misalignment is still a topic of debate, but best/prevalent idea is that it is related to the transmission.

 

Other factor is that in the designe for the 1150 & 6 speed, somehow the hub on clutch plate only goes about 2/3rds the wayt onto the xmission shaft. Some folks point to that as being "the cause".

 

Other factrors are the surging, maybe, and maybe the 6th gear being so tall. And how much those are factors would be variable in each riders case based on their habits (that is, what rpms they usually run, as an example)

 

And.... your spline has been wearing since day one, well, maybe not day one, it had some grease lube originally, so .... has been wearing away since very early on its life ... and was about to completely fail at some point soon.

 

And... we could chat about various repair options.

 

.

 

 

[JamesW]

So Dave, I'm just curious. Would you do it again based on your experiences with the pride of the Bavarian Motor Works?

[Marty Hill]

Cute question. Like buying a 13 year old car. Sometimes they are less than perfect.

[Froggy]

I have thought it over and will take apart in sections. That way I can see if any more problems. As for surging that is a continuing problem from day one. That's when I envy the R11500R riders with no plastics to take off twice a year for syncing.

[JamesW]

Cute question. Like buying a 13 year old car. Sometimes they are less than perfect.

 

Good point. I looked over this thread and I can't find any reference by the originator regarding total mileage on this '02RT when he purchased it. If a high mileage machine then maybe somewhat forgivable.

 

Theories are many on why this spline issue occurs. I think it not an accident that the 1100 machines with full clutch spline engagement with the trans input splines seem so trouble free in comparison to the 1150's. I used to think riding around in 6th gear at low speeds contributed to the problem and maybe that's true but I don't think it is the root cause and may not even be a contributing factor at all.

 

If my '04RT ever suffers this spline failure malady I will just call it a day and part it out. Of course it is easier to have this attitude as I'm the original owner so I've had many good rides and years of enjoyment on the big blue beast. Slight surge problem which an LC-1 cured (thanks Roger) and a couple of faulty stick coils isn't bad for 11 years and 50K miles, imo.

[Redman]

So Dave, I'm just curious. Would you do it again based on your experiences with the pride of the Bavarian Motor Works?

 

...... regarding total mileage on this '02RT when he purchased it. If a high mileage machine then maybe somewhat forgivable.....

 

OP here with Quick review:

02 RT

46K miles

bought it a couple months ago (out near where daughter lives), after having Suzukis from the 80, since the 80s, concerned about reliability of 32 year old bike.

(now, 3 weeks ago visiting daughter, riding in that area)

5th day of riding karunk zirhhhr zirrrrhhhrrr zirhhhhhrrr life-threating-experience coasting-3rd-lane-busy-highway.

 

Would I ever get another BMW 1150 ?

Would I ever get a newer BMW ?

 

Actaully... I may have to ask if I will ever get another bike at all in the remaining few years I may have left to ride.

Have blown my remaining life-time motorcycle budget on this thing. (purchase cost, + replacemnt parts, + repair cost, + maintentinace it was behind on)

 

(Have to deal with the Household Budget Committee, you know.)

 

Actually, at this point, I am still too annoyed to be making too much of an objective evaluation.

 

But, I CAN say: NO!, No, I am NOT happy with BMW.

Mostly due to my situation, and what this bike has done to me.

And partly from learning the history of what happened with these 1150s in the day when they were 2-3-4-5 years old.

 

Also keep in mind, that a typical BMW rider (that has two new bikes, has budget to buy a new bike every 2 year so neither is more than 4 years old, and wears gear where the jacket + pants + helmet cost more than my 82 Suzuki is worth) might say: well, you gotta expect that can happen with an old bike.

 

Well, for me, right or wrong, but for me this was/is a new bike (compared to an 80, 82, & 86).

 

 

Dave

 

 

 

PS: Although I must say I am more than happy with San Diego BMW.

From the 1st expereince when I first stopped in there on the 1st day with the bike... I was quite impressed.

They were so helpfull, and went out of their way to help.

I actaully felt like I was abusing their generosity.

And when I was back later on the 5th day (on tow truck), they were very helpfull, even though the service department wasn't open that day (the service manager made himself avaialble to take care of things. The owner came by to assist. The salesman was a salesman, but other thasn that....).

 

.

[Jim Moore]

I have thought it over and will take apart in sections. That way I can see if any more problems. As for surging that is a continuing problem from day one. That's when I envy the R11500R riders with no plastics to take off twice a year for syncing.

 

Try disconnecting the O2 sensor. It was the only thing that stopped the during on my GS.

 

If you do that and decide to leave it that way make sure you water proof the bike side of the connector.

[AndyS]

Dave, I am not sure if you have told us, but was the bike a private purchase or from a dealer?

[Trobinson]

All of this talk of the 1150 spline failures makes me happy with my '96 1100. 150k miles and feels strong. I did a wear check at the rear wheel and it's less than an inch IIRC. Haven't pulled the starter to do a visual, but perhaps that's in the near future (when I do the next TB balance/valve adjustment/tune-up).

[JamesW]

Hi Andy, kind of sounds like he bought it from a private party but I'm not really sure. In an earlier post he mentioned talking to the previous owner about the spline issue. He really got a pretty bad deal and I can certainly see why he feels the way he does. No way should that motorcycle have self destructed at under 50K miles i don't care if it is 13 years old. Anyone would be just a bit pissed off. I have been on BMW bikes since 1976 and have had few issues. That said the newest BMW I shall ever own is my '04 R1150RT which I purchased new and this is mostly because of my age (71). I also don't like the direction the marque has taken in recent years where quality, complexity, company philosophy, and customer service is concerned. And if Dave did buy this bike from a dealer then that dealer should refund his money. Just reading this thread irritates me no GD end!

[tallman]

"Also keep in mind, that a typical BMW rider (that has two new bikes, has budget to buy a new bike every 2 year so neither is more than 4 years old, and wears gear where the jacket + pants + helmet cost more than my 82 Suzuki is worth) might say: well, you gotta expect that can happen with an old bike"

 

Dave,

Sympathize with your situation.

 

But, I seriously think your "typical BMW rider" description is somewhat flawed.

If the typical BMW rider bought a new BMW every 2 years the annual sales for the marque would be in the hundreds of thousands

instead of the 13-15,000 range they are in this country (last I looked).

I know many who have never purchased a new one, including myself and my first was a '68 R50.

Now as to the value of an '82 Suzuki, well that is a different story.

Hope you have many trouble free and enjoyable miles ahead and this becomes a distant memory wrt you BMW experiences.

Best wishes.

[Redman]

Dave, I am not sure if you have told us, but was the bike a private purchase or from a dealer?

 

Private party, (advert on Cycle Trader).

 

Seems like a decent guy.

 

Said he didn't ride much since changing jobs 3 years ago, then last year had an injury where not riding at all anymore. Was "getting out of riding" (and wanting to get more into vintage Porsches). Gave me all his helmets (Bluetooth equipped), BMW bike cover, BMW batterytender, BMW jackets and such.

When talking about the bike he didn't seem too familiar with specifics of the mechanics, says he took it in for all the service, and gave me all the service papers.

 

I did contact him after this happened. When I told him about this spline failure, he didn't even seem to know what that was.

 

I did say that if he did know that this problem was eminent that other forces in the universe would take care of it for me.

 

 

.

 

[Redman]

"..........But, I seriously think your "typical BMW rider" description is somewhat flawed.........

 

TM,

 

THanks for your comments and observations.

 

Yah, I probably was overstating it some, just to make my point more obvious ... and venting some.

 

I usually am more calm and factual. Was venting some.

 

Dave

 

 

 

[Froggy]

I purchased mine used 4 years ago with 11,000 on mine from Arizona. Which meant it had never seen salt on the road. That was a plus for me. I could tell it was mainly highway due to chips on paint in front and very squared off tires.I always run my bikes at higher rpm's to keep load pressure off trans and engine (mechanics background). As for surging I installed a neat little device that fools 02 to send signal to run richer,not perfect but it reduces surging when out of tune. The dry clutch on a bike is a good idea if done properly, if not done properly...well the 1150s shows what happens when done improperly. Two thirds engagement is not "good enough" when considering punishing forces applied to the drive train on a bike. Would BMW feel it's "good enough" that the building they worked in was two thirds up to building code. A bit harsh but as the starter of this thread realized,loosing power on a highway can be VERY dangerous.

[roger 04 rt]

Bummer, bummer, bummer!

 

I remember there was a batch of '02's that were all slightly misaligned

 

 

This "fact" has been brought up over and over again but nobody knows where it came from, or actual data behind it.

 

I believe it comes from a poll on this forum sometime 5 or 6 years ago on clutch spline failures. The vast majority of failures was with the 2002 RT and then decreased yearly thereafter. My 2002 RT's splines crapped out at 42,000 miles, but I fixed it myself and sold the bike. It's still going strong and I wish I had it back.

 

I saw your post on the repair you made on the BMWMOA forum and though it would be a good addition here.

 

"... when my splines went out, I replaced everything south of the crank shaft. ( Clutch housing, clutch plate, pressure plate, and replaced the tranny input shaft, front shaft bearing, and all seals. ) I did not check for alignment as I don't have those skills. The original splines failed at 40,000 miles. It was an '02 RT. I took another look at the splines at about 70,000 miles just before I sold the bike. The splines were fine. ..."

 

[Rex R]

Morning Roger

 

Well common sense tells me the ones I have repaired have stayed repaired so what I did has worked well.

 

Talk & speculation is one thing but until people start measuring these things it is just that.

 

Hi Dirtrider,

 

What do you do during repairs that other techs/dealers might not do? My oilhead's splines have stripped (probably-haven't opened it up to verify) just 20k after the last failure.

 

 

 

 

 

[AndyS]

Hi Rex, sorry to hear about your bike. What model, mileage and year is it?

[dirtrider]

Morning Roger

 

Well common sense tells me the ones I have repaired have stayed repaired so what I did has worked well.

 

Talk & speculation is one thing but until people start measuring these things it is just that.

 

Hi Dirtrider,

 

What do you do during repairs that other techs/dealers might not do? My oilhead's splines have stripped (probably-haven't opened it up to verify) just 20k after the last failure.

 

 

 

 

 

Afternoon Rex

 

Basically I check then correct any engine crankshaft to transmission front bearing mis-alignment.

 

Maybe a few (caring) independent BMW shops might do this but no dealer that I know of does it & most wouldn't even know how if you asked them.

[nrp]

Since it has failed so repeatedly, you most certainly have a radial alignment error between the transmission axis and the crankshaft axis. If you want to measure it, my measurement rig is in Vancouver BC right now although he has ways to get it back in this country for mailing to you. I can make you a couple of offset alignment pins that will correct a measured misalignment.

 

Or you can start replacing parts and hope you replace whatever part has been manufactured incorrectly.

 

You probably have a worn/loose rear crankshaftmain bearing which is a result of operating with this as-maufactured misalignment. Replacing the bearing shells means splitting the engine, but I'm unaware of anyone doing that.

 

There are a couple of threads at pelican parts website that pictures and document the measurement procedure.

 

There are a lot of threads on all the oilhead forums on this topic.

 

Tough break.

[nrp]

Check:

 

http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/845339-well-i-bought-r11s-trans-failure-6.html

 

Start at about post 100 for measured results. There is another slightly later posting at pelicanparts by SpaffyPD which documents his measurements with pictures. That rig is now in Canada.

[nrp]

The summary of SpaffyPD's measurements and pictures is at:

http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/863118-results-spline-replacement-bike-overhaul.html

[roger 04 rt]

Esmir asks a very important question that I'll post here since I'm not a member at pelican parts:

 

Good job.

Let the test begin.

It will be interesting to see long term results.

BTW, how many miles on the bike and could you tell if the clutch plate was original?

One thing that is missing is the measurement from a "known good" transmission to compare against. Of course, it would have to be done with same tools, and ideally same person doing the measuring. Unfortunately, chances of that are slim to none. It would also be good to actually verify the out of round main bearings, (since it is also assumed) but that is not going to happen either.

 

This is a good "pre failure" example.

Interesting thing is the shape of the splines on the shaft versus the clutch. If I am seeing correctly, clutch splines are worn, (except for the not used portion) but still almost straight without the signature scalloping that is seen on the shaft.

Can anybody offer explanation for this?

[nrp]

The single-direction out-of round (actually the clearance variation) of the main bearing shell is documented in Spaffy's report. That clearance variation was in a direction consistent with the direction of the measured alignment error, and is well outside (like 3 times) the published BMW main bearing wear allowances.

 

It looks to me that Spaffy's clutch hub's engine-end could well be fully stripped and that things were operating with only a smidgen of transmission-end engagement.

 

I think it is safe to assume fretting wear only takes place where there is contact. The clutch disk hub in Spaffy's case should be sectioned to match the spline tooth wear profile to the shaft. I'll approach him on that.

 

It is interesting that his transmission was above and slightly to the right of the engine center, and the very few others that have actually measured the alignment have noted the same. I don't know of any others that have looked at the main bearing wear profile.

[cele0001]

I think it is safe to assume fretting wear only takes place where there is contact.

 

Profound statement. I completely agree. If two things are not touching, they will not wear on each other. The back end of the shaft is not worn at all since the hub doesn't get there, and the bottom end of the hub is not worn at all, since the shaft doesn't get there.

 

 

Here is the "non conjugal" wear on one of the latest repairs.

This is not a speculation. This IS a fact. This is what the wear looks like, ALWAYS.

 

[roger 04 rt]

Hi Neil, As an interested novice at this, I'm really delighted to see your efforts to help others measure the runout on their bikes. Although I accept that non-aligned centers of rotation is an issue, I would find it more satisfying if the theory of failure explained the different wear patterns on the two mating parts. The clutch hubs wear in a straight line but the transmission input shafts wear on an angle. This pattern is seen in every photo I've looked at.

 

Looking at the data below from the link I've provided, I interpret the data, as presented, to show 0.000 runout at some points, increasing to 0.0115" at the peak value. This means the centers are misaligned by half that figure, which is 0.00675".

 

For the crankshaft play, I will present them in pairs

7/8 vs 1/2 : 0.001 vs 0.006 center is 0.25 toward 1/2 o'clock

12 vs 6 : 0.0065 vs NA delta is (assuming 0.00175 for 6 o'clock) 0.002375 toward 12 o'clock

9 vs 3 : 0.0015 vs 0.003 center is 0.00075 towards 3 0'clock

4/5 vs 10/11 : 0.0025 vs 0.004 center is 0.00075 towards 11 o'clock

 

So the raw centerline deviation is 0.00675", but the crank while measuring the runout was (using 7/8 vs 1/2 o'clock) is 0.0025 off its center toward 1/2 during the runout measurement. That error is opposite the direction of runout. So I suggest the actual centerline deviation is 0.00675-0.0025=0.00425". Is a 4.25 thousandths of an inch error causing the wear we're seeing?

 

I completely agree that runout errors can lead to significant wear. But how is insertion factoring into this, and what is the dynamic motion of the pieces?

 

These were the reading I got from measuring the transmission input bearing race:

TIR reading: 0.0115" with the maximum reading at the approximately 7-8 O'Clock position. So the transmission is high and right.

 

As a reference I measured the play in the rear main bearing and these are those numbers:

 

12 O'clock- .0065"

1-2 O'clock- .0060"

3 O'Clock- .0030"

4-5 O'clock- .0025"

6 O'clock- wasn't able to get good leverage- no reading

7-8 O'clock- .0010"

9 O'Clock- .0015"

10-11 O'clock- .0040"

[nrp]

I think if the hub was cut over for direct radial viewing, you would have to see conjugal wear on the teeth. Frankly I have never had the chance to see a partially worn spline set as they seem to only be discovered after they strip out. But the wear of a strip out will probably be unevenly distributed between the two elements. That's what causes the spiral wear pattern.

 

Fretting wear under poor or non-existent lubrication can easily happen with tiny motions - well under the .0085 inches DOUBLE amplitude, but the wear could be a divergent thing where it feeds on itself so that you get it in spades or not at all. There will be an additional divergent contribution from the increased main bearing clearance.

 

I doubt the small amount of possible additional spline insertion could answer the wildly life variations we are seeing in these service failures.

 

In engineering hindsight (which is always 20/20) BMW could have made an airgaged setup to quickly check alignment on each bike on assembly.

[roger 04 rt]

But Niel, what about the math from the pelican parts link? There is only 4.25 thousandths of centerline difference.