Clutch Splines Again! Questions

[Jim Moore]

Folks,

 

I pulled my transmission (R1100S at 40K miles) and sent it off to have it repaired because of bad clutch splines. Now, 15K miles later, it's happening again. I have a good 1/8 inch of play between the shaft and the disk, measured at the edge of the disk. I may tackle this job next weekend and I have a few questions.

 

1. How much is 1/8 inch of play? Do I have thousands of miles left, or is it ready to blow? Does anyone have any data there?

 

2. I'm considering throwing a new clutch disk in there and seeing what happens. An additional 10K miles for the price of a clutch disk would be a reasonable deal in my mind. I know a few people have gone this route. How have your results been? (Btw, do I need new clutch bolts?)

 

3. I also have a used (66K) transmission with good splines in the garage. What are the chances of the different transmission solving the problem? Any ideas?

 

4. Anyone have an alignment tool I can rent?

 

Thanks,

 

Jim Moore

[dirtrider]

Morning Jim

 

 

 

You ask----

 

I pulled my transmission (R1100S at 40K miles) and sent it off to have it repaired because of bad clutch splines. Now, 15K miles later, it's happening again. I have a good 1/8 inch of play between the shaft and the disk, measured at the edge of the disk. I may tackle this job next weekend and I have a few questions.>>>>>

 

Difficult to tell, with the clutch lever pulled in the disk drops down on the splines so some of what you see is not as it runs down the road. If the 1/8" is actual that doesn't sound like immediate failure but the splines could be worn very angular & about to fail so you really should pull it apart for inspection.

 

1. How much is 1/8 inch of play? Do I have thousands of miles left, or is it ready to blow? Does anyone have any data there?>>>>

 

No way to tell for sure, possibly & maybe not. Depends on the actual wear on splines & spline engagement on the input shaft, not disk movement.

 

2. I'm considering throwing a new clutch disk in there and seeing what happens. An additional 10K miles for the price of a clutch disk would be a reasonable deal in my mind. I know a few people have gone this route. How have your results been? (Btw, do I need new clutch bolts?)>>>>>

 

That is probably a good place to start. That will give you a close up inspection of the splines & input shaft. Might not even need the new disk depending on what the spline wear looks like at inspection. Yes to the new bolts.

 

3. I also have a used (66K) transmission with good splines in the garage. What are the chances of the different transmission solving the problem? Any ideas?>>>>>

 

IF (big "if" here) you DO have abnormal spline wear appearing "again" at ONLY 15K then you have some sort of a severe mis alignment issue. Either a trans alignment problem or a crankshaft centering issue or severely worn rear main bearing. (something not aligned correctly). Installing a different trans should at least change that part in the alignment string. At least you are doing SOMETHING differently than before.

Personally, I would set up a dial indicator on the crankshaft & sweep the front bearing bore in your present trans housing & the other trans housing. If one is better than the other then use that one & make up some offset trans aligning pins to correct the remaining centering issue.

Bottom line here-- if you do NOTHING except install a new clutch disk your problem will be right back AGAIN.

 

 

 

 

4. Anyone have an alignment tool I can rent?>>>>

 

If you get to the point of needing an alignment tool give me a PM I have one you can use (just cost you shipping both ways). Even though I seldom use it any more I don't like to part with it for a long time (in case I do need it) so only PM me just before you actually need it.

 

 

If your bike were mine & having a (known) history of failing the trans splines & just re-installing the original trans as it was I would be pulling it apart for spline inspection. At least that way you will know for sure where you stand on the spline wear issue at the 15K mark. If not too bad now maybe a new clutch disk "only" will buy you another 10K. At least you should know where you stand mileage vs spline wear.

 

[Stan Walker]

1. How much is 1/8 inch of play? Do I have thousands of miles left, or is it ready to blow? Does anyone have any data there?

 

I measured this on my R1150RT when I last lubed the splines at 70,000 miles. As I recall it was just over 1/8 inch of rotation at the edge of the disc. This was with the original clutch disc and input shaft which were in almost perfect condition. Both are still in the bike over 40,000 miles later.

 

If it were my bike I would consider 1/8" normal and check it again next year. YMMV

 

Stan

[Jim Moore]

thanks Stan. it was your original post from long ago that led me to check them in the first place. I really appreciate it.

 

is there any wayI can talk you into going out to the garage and taking a measurement for comparison?

 

As a note, 1/8of an inch at 70K miles is probable nromal wear. 1/8 at 15K miles is a disaster waiting to happen, especially given the history of this bike.

[cb75076n99]

Jim,

Regarding the clutch alignment tool - I have 106,000 miles on a 1996 R1100RT and I just replaced my whole clutch set (everything but the flywheel) and the trans input shaft. For a clutch alignment tool, I used the clutch pushrod and duct-taped a socket so that it fit snug inside the clutch splines. Or you could also use your transmission with trans input spline (don't need the clutch pushrod for this), if you don't mind gently sliding the trans back on temporarily just far enough to center the clutch. I ended up doing that, too, (belt and suspenders, I guess) and then tightening the clutch bolts via the hole where the starter goes, and that wasn't difficult. I rotated the clutch assembly for gradual tightening, by turning the bolt at the front where the alternator belt is. You might know this already, but it is important to match the marks (they denote a weighted spot) on the 2 clutch components and flywheel so that they are centered as close to 180 degrees apart as possible (mine lined up more or less close to that, but not exactly, and that worked out fine). If you are only replacing the clutch friction disk, be sure to mark the components yourself before you remove them because the original marks may be hard to find. If you purchase new components, they will be marked clearly.

 

Good luck.

 

Jerry Holtz

Maplewood NJ

[Stan Walker]

is there any wayI can talk you into going out to the garage and taking a measurement for comparison?

 

Maybe early next week, I need to service this bike anyway to get ready for a trip. Would that be soon enough?

 

I've actually been curious about this. Curious to see if it has changed in the last 40 K miles.

 

Stan

[Jim Moore]

Sure, that would be great. Thanks.

[Stan Walker]

Sure, that would be great. Thanks.

 

OK, I'll follow up and get back to you when I do.

 

Stan

[notacop]

I guess I was lucky. I bought a used RT-P from the CHP with 60K miles on it and traded it in with 122K miles on it and never gave a thought to the clutch or anything else except for the HES which took a sh-t. Some things are best left alone. I did check valves occasionally but didn't have to make much of any adjustments.

I did notice that it was very easy to mess things up and aggravating to make them right again. Less is more!