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Checking for spline wear 1999 R1100S

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The pictures above show a conjugal wear pattern.

No, they are on their way to looking like this:

spline.jpg


Now, trust me on this: the splines on the clutch disk remain straight as they wear. You can see that in the pictures, too.
 
That photo is from May 2010 and there are a lot of shafts that didn't make the picture. Many owners want the dead input shaft back as a souvenir, and of course i have repaired many since then. i'm guessing my dead input shaft drawer has about 20 or 25 in there, and nearly all are from 1150s.
 
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No, they are on their way to looking like this:

spline.jpg


Now, trust me on this: the splines on the clutch disk remain straight as they wear. You can see that in the pictures, too.

The photos you've shown attest to just how much experience you've got with this problem. The shafts look so similar, do you believe the cause is the same for all of them? How many miles on the shafts you've shown? Do you replace parts or try and work out alignment errors? Thanks for these interesting photos. RB
 
My gut feeling with those pictures is mis-alignment.

We had a schwack of excavators that did the exact same pattern on the pump drives. The housing face had been machined off kilter a bit and affected every machine within about a 1000 range of their serial numbers. We were fortunate enough to have about 100 of them in that serial number range and not one ever failed under warranty.

I also wonder about the hardness of the input shaft. Obviously you can't have the shaft super Rockwell hard matched by the clutch hub.

There was a time if my limited memory can conjure up the exact reason, but back with my first Beemer Thumper, I'm sure the service manual said to take the tranny out and lube the clutch/input spline every 10k miles.
 
I would bet that the input shaft is induction hardened, and that hardness tests will show them to be hardest at the very end where things self quench. The hub is probably of more equal hardness throughout its axial length as it is probably furnace heated and dropped into a quenching media.

I agree most of the shaft wear takes place towards the transmission, but there is no way the hub-shaft system can wear non conjugal.
 
I agree most of the shaft wear takes place towards the transmission, but there is no way the hub-shaft system can wear non conjugal.

It might be more accurate if you said that you don't understand how they can appear to wear non-conjugal.

For everyone else reading this thread, you might want to read this thread instead:
http://forums.bmwmoa.org/showthread.php?56977

Same thing. The parts must wear the same way, what do you mean they don't, have you ever seen them wear differently, OMG you are right look at the pics, etc. Start at post 50 or 60 if you don't have time for all of them.
 
For everyone else reading this thread, you might want to read this thread instead:
http://forums.bmwmoa.org/showthread.php?56977

I sure thought there was a similar lengthy discussion a few years back... :scratch

H's '02 1150 R had it's third lube since we have owned it last Spring and is at 108K. The first time it was red/rusty and the last showed some spline wearing that I plan on addressing at the next interval. This was her primary bike until last year, so it may take a while to get the miles this time.

I just hope she is not riding in the boonies like Voni was on River Road and I get a "friendly" call :hide But if it happens..it happens as the bike is 13 model years old .

Her '95 1100R needed a clutch at 50K...the PO must have really slipped the clutch..a LOT! H said she did as she had on her H-D ,but learned quickly to not do that, so I think the damage was already there. The splines looked pristine, the disc was way under specs. It got a complete clutch pack.

Our '99 11S has low miles and had the surgery two years ago...all looked good then.

I always wondered if how much one uses the clutch is a factor...East coast density vs. Western states open range primary riding, or clutch held in at every stop instead of neutral. Just thinking...not caring really:whistle
 
HW,
That's about how mine looked.

I've read in other posts that debris (reddish or blackish) in the flywheel/clutch housing area is an indication of wear. It looks like you have some reddish dust in the video. What do you attribute that to and also I'd be interested in what kind of dust clutch disk wear (normal) would deposit.
RB

I'm not sure what the dust in there was coming from but initially suspected dried up grease turned to dust and flung about. Then I saw a tube of OEM Starburag grease and it's not that colour. I am hoping to get in there this winter at some point and find out. It's due for a spline lube.

I forgot to mention that while the movement may seem like quite a bit in the video one needs to bear in mind the distance from the spline contact point to the outer edge of the clutch disc amplifies this movement by quite a bit. Well, at least I am hoping it does! ;)
 
It might be more accurate if you said that you don't understand how they can appear to wear non-conjugal.

For everyone else reading this thread, you might want to read this thread instead:
http://forums.bmwmoa.org/showthread.php?56977

Same thing. The parts must wear the same way, what do you mean they don't, have you ever seen them wear differently, OMG you are right look at the pics, etc. Start at post 50 or 60 if you don't have time for all of them.
That was quite a thread! I reread the whole thing & I still agree with what I posted there two years ago. A couple of points on reflection:

1) Maybe the reason FWD automobile splines don't fail from manufacturing errors (per post 34 by jconway607 of the referenced thread) is the slight radial compliance of the clutch damper spring system. Our bikes have no torsional damper springs, but instead only a flex plate which is probably radially a lot stiffer. As a result we are probably a lot more sensitive to clutch housing manufacturing errors.

2) I think ferrous oxide (the grey wear debris stuff inside failing clutch housings) is still magnetic, but clutch disk wear products are probably not. If so, sweeping the area around the spline with a magnet with the starter removed would show the relative quality of the alignment-caused wear a particular bike. At least it might be better than simply a visual evaluation.

3) Just maybe there is a greater clutch spline wear contribution from the crankshaft main bearing clearance than we have been realizing. Do you check for rear main bearing clearance in all radial directions when you find a bad spline system? I read in the Pelican Parts site post by Bill Pierce that he only saw like .0015" clearance. I wonder if he misread the indicator (unlikely given the quality of the rest of his posts) or if he didn't happen to check in the worst direction?

When I did my sole spline failure forensics, I found reasonable main bearing clearance in one axis, but over .007" in an odd direction - sort of like the bearing shell was worn in a race track or oval manner. It didn't require a dial indicator as the clunk would have been obvious to anyone handling the screwdriver pry bar.

4) (edit) I tried keeping the transmission slightly loose (as I proposed in a post in the referenced string) from the engine when I re-did spline lube on my R90/6 a year ago. There was a quite perceptible "breathing" between the two whenever the clutch was let out, but I was unable to find a happier combination that allowed the transmission to align any better with the engine.

You are correct that maybe I should have said I don't understand how these splines wear, but I know gear theory (splines are a subset of gears), manufacturing practices, and failure forensics from elsewhere, including the school of very hard knocks.
 
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all oilheads take the same clutch disc, this is what you want to do. pop the rivets and install a 3/16 shim between hub and disc itself. you will need longer rivets and to shorten up your pushrod 3/16inch as well. bmw should be ashamed at the release of such a debackel, happy motoring, and run em like ya stole em.

Hang on... They are not the same. The 1100 and 1150 have different clutch disc part numbers. And if you go back to post 15 this misconception has already been corrected from someone who fixes them every day for a living.
http://forums.bmwmoa.org/showthread.php?71138-Checking-for-spline-wear-1999-R1100S&p=911234&viewfull=1#post911234
 
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all oilheads take the same clutch disc, this is what you want to do. pop the rivets and install a 3/16 shim between hub and disc itself. you will need longer rivets and to shorten up your pushrod 3/16inch as well. bmw should be ashamed at the release of such a debackel, happy motoring, and run em like ya stole em.

That is almost complete hogwash.
 
Anton, Are the number of spline failures roughly the same whether its a hydraulic clutch or cable operated?
 
The failures seem FAR more common on the R1150-type 6-speed, which happens to be hydraulic. There is no transmission/clutch design which has both cable and hydraulic for comparison.
 
The shafts look so similar, do you believe the cause is the same for all of them? How many miles on the shafts you've shown? Do you replace parts or try and work out alignment errors?

30k miles seems like a typical failure point if the bike is going to fail, and the failures seem the same to me. I see gradual wear on many other bikes at higher mileage, but there seems to be a cluster of failures around 30k. I think I have described in other threads how I replace everything, and how I came to that.
 
30k miles seems like a typical failure point if the bike is going to fail, and the failures seem the same to me. I see gradual wear on many other bikes at higher mileage, but there seems to be a cluster of failures around 30k. I think I have described in other threads how I replace everything, and how I came to that.

I read through everything linked through these posts and understand your approach now thanks. You've been very generous with your knowledge and data.

I think I have some wear (30K miles) with 1/16" movement at the perimeter of the clutch disk. Big issue for me is do I open it up to lube and inspect. When I eventually do, if it needs an input shaft, the transmission will be headed your way. That operation would be beyond my experience and it's not something I'd want to learn on the job.

I am still fascinated by the consistency of the curved, sculpted, wear pattern on the input shaft. I am starting to believe there would be merit in a full input shaft to clutch hub engagement.

RB
 
I have to eat some of my words that Anton has been complaining about.:banghead

I now contend the reason most of the transmission input shaft spline wear occurs closest to the transmission on virtually all his pictures, is the radial load on the spline has to be approximately centered under the flex plate (clutch spider plate). The flex plate is not attached to the clutch hub at its longitudinal center. Instead it is located closer to the transmission end than the engine end. This can be seen by comparing the numerous photos of clutch hubs that are taken from the engine end. Photos from the transmission end are almost non-existant, but I found ONE in the last photo of post 70 of the above referenced Pelican Parts thread.

This revelation suggests to me that 1) additional spline engagement proposed by others (i. e. manufacturing a longer hub to get 1/4 inch more engagement) at the engine end will not offer any benefit, and 2) anything that moves the hub still closer to the engine (i. e. Ratze suggested adding a spacer under the rivets in post 32 above) will actually worsen the radial load carrying capability of the spline elements.

Later (2-10-14) I now don't think the flex plate has much to do with the wear pattern. It has to be progressive due to the harder shaft spline near the tip. The sharply curved wear pattern on some of Anton's PIX have to be due to a failed spline - not just a worn one.

This also means that the worn spline surfaces may not be exactly conjugal (Anton's contention and his photos), as the hub axis is deforming non parallel (under radial load in the presence of misalignment) to either the engine or the transmission axis. The flex plate (clutch spider) allows such deformation. Being conjugal requires the rotation axes to remain fixed in service. The flex plate eliminates this possibility.

Can we agree on this?
 
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