Question about R1150RS clutch spline wear

[justmike]

I know this is an old topic, but from reading as many threads as I could find I have a question that I didn’t see addressed. I have a 2003 R1150RS that I bought as a wreck in case I needed parts for my new to me 2002 R1150RS. Shortly after buying the 2002 I started coming across all these stories of early clutch spline failure and figured I better have a plan, just in case, hence the purchase of the 2003 parts bike. My 2002 has 36k kms, on it, the wrecked 2003 has 29k kms.

Well, upon disassembling the 2003 I quickly discovered that the clutch and input shaft splines have an extreme amount of wear. The wear in the hub of the clutch plate appears to be about 50%. It also appears that the wear is uniform from one end of the splines to the other ie. the spline width remains constant front to back.  The input shaft has a bit less wear, but is angular - the spline width is tapered, being narrower towards the transmission end of the spline, wider at the engine end. I have disassembled the transmission and measured offset and got what seems to be a typically reported 0.009” offset towards the 2 o’clock position. I’d say mine is more like 1:30. 
My question is this. How do you account for taking this measurement using the end of the crankshaft, and not the actual bearing bore. Recognizing that there is clearance between the bearing shell id and the crankshaft OD, when static is the crankshaft not sitting “off-centre”. As I index the crank to take the various measurements, is gravity not causing the crank to drop in every position, resulting in a false measurement. I tested this by using a screwdriver to pry and lift the flywheel, and this changed the reading notably. Thoughts?

Someone on the board suggested to me that flywheel axial runout is more likely the cause of the problem. I checked this on the three mounting ears, and using one as zero, the other two were out 0.012” and 0.014” . I might have to recheck these measurements because I wasn’t particularly careful to ensure crankshaft endplay was a factor.

Any advice would be appreciated. I’m basically using this spare engine/transmission as a learning experience before I pull apart my actual bike. 

Attached photo @ 29k. kms.

[dirtrider]

15 minutes ago, justmike said:

I know this is an old topic, but from reading as many threads as I could find I have a question that I didn’t see addressed. I have a 2003 R1150RS that I bought as a wreck in case I needed parts for my new to me 2002 R1150RS. Shortly after buying the 2002 I started coming across all these stories of early clutch spline failure and figured I better have a plan, just in case, hence the purchase of the 2003 parts bike. My 2002 has 36k kms, on it, the wrecked 2003 has 29k kms.

Well, upon disassembling the 2003 I quickly discovered that the clutch and input shaft splines have an extreme amount of wear. The wear in the hub of the clutch plate appears to be about 50%. It also appears that the wear is uniform from one end of the splines to the other ie. the spline width remains constant front to back.  The input shaft has a bit less wear, but is angular - the spline width is tapered, being narrower towards the transmission end of the spline, wider at the engine end. I have disassembled the transmission and measured offset and got what seems to be a typically reported 0.009” offset towards the 2 o’clock position. I’d say mine is more like 1:30. 
My question is this. How do you account for taking this measurement using the end of the crankshaft, and not the actual bearing bore. Recognizing that there is clearance between the bearing shell id and the crankshaft OD, when static is the crankshaft not sitting “off-centre”. As I index the crank to take the various measurements, is gravity not causing the crank to drop in every position, resulting in a false measurement. I tested this by using a screwdriver to pry and lift the flywheel, and this changed the reading notably. Thoughts?

Someone on the board suggested to me that flywheel axial runout is more likely the cause of the problem. I checked this on the three mounting ears, and using one as zero, the other two were out 0.012” and 0.014” . I might have to recheck these measurements because I wasn’t particularly careful to ensure crankshaft endplay was a factor.

Any advice would be appreciated. I’m basically using this spare engine/transmission as a learning experience before I pull apart my actual bike. 

Attached photo @ 29k. kms.

 

Morning  justmike

 

Yes, that can be a problem if your engine has a lot of rear main bearing wear, or is just a loose one from the factory.

 

I usually remove all the spark plugs (that takes the compression lateral load off the crankshaft), I remove the alternator belt (that takes the  vertical lift off the front of the crankshaft). 

 

Then (if possible) I will run the engine over on the starter to build a little oil pressure & oil the rear main bearing. 

 

Then after zeroing the dial indicator in the trans front cover input shaft bearing bore I turn the crankshaft using only the front pulley bolt (as smooth & steady as possible)

 

Then I take multiple readings & average the findings.  

 

It isn't perfect but about the best you can do if you have a loose rear main bearing. 

 

.009" (nine thousandths of an inch) measured  is a lot of offset & will usually give fairly quick spline wear. 

 

 

[justmike]

Thanks for that Dirtrider. I did my measurements pretty much as described with the exception of spinning the motor with the started, although I did crank the motor quite a few times with a wrench on the front pulley to the point of oil level dropping from view in the sight glass. I forgot to mention that the front bearing on the input shaft is loose - almost imperceptible radial play, but it spins very freely and the outer race tips side to side more than I’d expect.

Just to confirm, below are the readings I got - 10 times and last column is the average. So at 0.009” thereabouts, the input shaft bearing bore would only be off centre by about 0.0045, so that should be the offset of dowel pins if I go that route?

Any thoughts on the flywheel runout?

[dirtrider]

2 hours ago, justmike said:

Thanks for that Dirtrider. I did my measurements pretty much as described with the exception of spinning the motor with the started, although I did crank the motor quite a few times with a wrench on the front pulley to the point of oil level dropping from view in the sight glass. I forgot to mention that the front bearing on the input shaft is loose - almost imperceptible radial play, but it spins very freely and the outer race tips side to side more than I’d expect.

Just to confirm, below are the readings I got - 10 times and last column is the average. So at 0.009” thereabouts, the input shaft bearing bore would only be off centre by about 0.0045, so that should be the offset of dowel pins if I go that route?

Any thoughts on the flywheel runout?

 

Afternoon  justmike

 

Yes, about .0045" offset pins would be a good starting point, cut a screwdriver slot in the outer end so you can turn the pins until you get the lowest runout reading. 

 

When you are referring the flywheel are you referring to the "Clutch Housing" (part with the starter ring gear on it? 

[justmike]

13 minutes ago, dirtrider said:

Afternoon  justmike

 

Yes, about .0045" offset pins would be a good starting point, cut a screwdriver slot in the outer end so you can turn the pins until you get the lowest runout reading. 

 

When you are referring the flywheel are you referring to the "Clutch Housing" (part with the starter ring gear on it? 

Re: 0.0045” - Do you think I should make some allowance for the settling of the crankshaft?

 

Yes, the part with the ring gear and the three “ears” that the clutch assembly fastens to. I indicated the faces of those three ears. Did my best to prevent axial  movement of the crankshaft. I’ve read that this part is a stamping, not machined, and in some cases does not run true, so the face of it wobbles during rotation, and so of course the clutch assembly  and splined hub is going to wobble too. I could see how this would account for the “tapered” wear on the input shaft. I can see how misalignment could cause this too, as the back end of the splines are some distance from the axial centreline of the clutch disc, with the misalignment causing a bit of a tipping action of the hub. Not sure how to tackle that. I’ve read some tried matching that surface true, but that caused other problems. Others tried shimming, but that also had its’ problems. Other just bought another “flywheel” - don’t really want to go that route if I can help it.

 

 

[dirtrider]

2 hours ago, justmike said:

Re: 0.0045” - Do you think I should make some allowance for the settling of the crankshaft?

 

Yes, the part with the ring gear and the three “ears” that the clutch assembly fastens to. I indicated the faces of those three ears. Did my best to prevent axial  movement of the crankshaft. I’ve read that this part is a stamping, not machined, and in some cases does not run true, so the face of it wobbles during rotation, and so of course the clutch assembly  and splined hub is going to wobble too. I could see how this would account for the “tapered” wear on the input shaft. I can see how misalignment could cause this too, as the back end of the splines are some distance from the axial centreline of the clutch disc, with the misalignment causing a bit of a tipping action of the hub. Not sure how to tackle that. I’ve read some tried matching that surface true, but that caused other problems. Others tried shimming, but that also had its’ problems. Other just bought another “flywheel” - don’t really want to go that route if I can help it.

 

 

Afternoon  justmike

 

On the crankshaft sag, if you have enough crankshaft movement to make a notable difference then you should probably be thinking of replacing the rear main bearing. I usually just adjust the  trans front cover bearing hole to be centered on the rotating crankshaft & call it good.

 

On the clutch housing ear height variance, good question, I would probably just fixture it in my mill & face all the ears to be the same height (or just  replace the clutch housing).

 

Without a mill you could probably epoxy a file to a straight bar then use that to hand file the high ears lower using the lowest ear as a file guide.  

 

If you have .009" of misalignment than that is your main contributor to the spline wear. 

 

 

[justmike]

Thanks very much for that advice DR., and taking the time to deliver it - very much appreciated. 
I half expected the “rear main bearing” suggestion. Obviously the right thing to do if there is a lot of play (I’ll re-measure that) but certainly not looking forward to that job. I’m sure hoping the splines in my daily rider don’t have this problem. What are the chances, eh?

Food for thought on the clutch housing. I’ll have to revisit the post where somebody did that type of fix but ran into another issue, I think with the surface where the clutch spring seats not being parallel to the three ears. Doesn’t make a lot of sense but I probably just misunderstood.

Again, thanks a bunch 👍