Checking for spline wear 1999 R1100S

[MotorradMike]

I remember a time when I understood the difference between Ferric and Ferrous. Gone now. Really though, some of the greases that wick should work fine? Warm the grease in the syringe like you do for Torrington bearings? Why not try?

You would know after some miles when you saw the Ferric or Ferrous oxides. Ferric Oxides are the crystal formation?

One of the things you have to be really careful about is to not get any grease on the clutch side or it will spin off and foul the friction disc.
The best spline maintenance to date seems to be:
Disassembly.
Thorough cleaning.
Grease only the input shaft, not the clutch spline, with something heavy and sticky like 'guard dog moly'.

I'd be concerned about anything thin enough to run going all the way through to the clutch side.

[Blacque Jacque Shellacque]

How do you mean that? It's a different plate, with a different hub, different spline and a different diameter.

No question a major brain cramp on my part, I apologize. It seems I was looking at the wrong fiche when cross referencing the parts.

[nrpetersen]

If you compare the shaft spline tooth wear with the clutch hub wear, you will see that the tooth wear on both will remain compatible (and that's not the official word I want). It has to wear that way as if there is a high point on one only, it will wear to a low point on the other element. What you are looking at is the differential hardness of the two elements. Where one is harder, it will wear the softer opposite, and vice versa. It has to be this way.

I had not thought of using heat to soften the grease for injection, but that may work using a heat gun. (good idea!) I have proposed using a small amount of volatile solvent (like lacquer thinner) to thin the grease temporarily so it can be injected into the gap. The solvent would evaporate in a few minutes. It takes very little solvent to thin grease. Experiments are in order.

It is important that ALL spline face surfaces get some lubrication as in operation there is no exchange of lubrication between teeth of a spline, much less even across the teeth. Some way of injecting a controlled but minute amount of lube is needed. I thought maybe an insulin syringe with a larger needle might work. The needle diameter has be to be less than about .030 inch according to my measurements. Frankly I've never tried it though.

The potential of an extra 20% of spline engagement would be nice I suppose but it really isn't the golden screw solution when spline wear is encountered. Alignment is what causes the fretting corrosion. Lubrication will cover some of the wear problem. Misalignment won't be helped by a longer spline.

[AntonLargiader]

If you compare the shaft spline tooth wear with the clutch hub wear, you will see that the tooth wear on both will remain compatible (and that's not the official word I want).

What is the official word you want?

If you mean that the parts will mate properly, I would expect a person with no experience at all to hypothesize that way. In reality, the clutch disc wears straight and the shaft splines wear curved, with a scallop at the rear. There are pictures of this all over the internet, you don't even have to leave your computer. Haven't you seen them?

[nrpetersen]

What is the official word you want?

If you mean that the parts will mate properly, I would expect a person with no experience at all to hypothesize that way. In reality, the clutch disc wears straight and the shaft splines wear curved, with a scallop at the rear. There are pictures of this all over the internet, you don't even have to leave your computer. Haven't you seen them?

I thought of it later - Conjugal.

If the input shaft teeth are narrowest at the transmission end (as you describe), and the disk hub teeth unworn, why doesn't the engine end carry all the torque and alignment-caused radial load? (Actually the alignment-caused radial load is the killer here)

You would have to measure the shaft teeth and hub teeth with pins etc or use bluing to determine how the teeth flanks are contacting. Photography has no way of showing the hub wear profile without cutting the hub in half longitudinally. If you did cut it longitudinally, the surfaces would be visually conjugal, I'm certain.

Is there a clear pair of pictures elsewhere you are referencing? The pictures above show a conjugal wear pattern.

[AntonLargiader]

Attachment 42630Attachment 42631Attachment 42632Attachment 42633

The pictures above show a conjugal wear pattern.

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



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

[AntonLargiader]

And lest you think that that was an anomaly:

[GSAddict]

And lest you think that that was an anomaly:

I jealous, your collection is bigger than mine!

[AntonLargiader]

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.

[roger 04 rt]

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



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

[dieselyoda]

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.

[nrpetersen]

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.

[AntonLargiader]

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.

[henzilla]

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...

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 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

[happy wanderer]

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!