R1100RT trans and clutch splines bad?

My RT has 73k miles on it (bought it when it had 55k). After reading about the importance of spline lube, and determining that the bike likely never had that service, I pulled the transmission. I took pics of the splines which were bone dry. The trans shaft splines show some thinning. And the clutch splines appear to be pretty much worn to triangular cross sections. After proper lubing can these make it another 40k miles? Thanks!

The clutch disk is toast for sure. I can't tell about the transmission shaft. Can you post a clearer close up of the transmission shaft splines?

PGlaves said:

The clutch disk is toast for sure. I can't tell about the transmission shaft. Can you post a clearer close up of the transmission shaft splines?

Click to expand...

I agree, the clutch is shot. The shaft? Not sure, clean it up, wire brush it, get the rust off and take another picture, close up of the splines. My gut tells me it will run, but a better picture would help.

PoorUB said:

I agree, the clutch is shot. The shaft? Not sure, clean it up, wire brush it, get the rust off and take another picture, close up of the splines. My gut tells me it will run, but a better picture would help.

Click to expand...

That was my original hunch but I need a better photo. Folks should keep these photos for every thread where somebody asks why they need to lube splines since they didn't need to in their Pinto or Fiat.

I enlarged the picture (ctrl +). I would use the transmission shaft as is. There doesn't seem to be that much spline debris around the face of the transmission. Had you washed it off?.

A better closeup picture would confirm everyone's opinion.

I agree with the other opinions given so far. Clean up the shaft, lube it and put a new friction disk on. The photo I'm adding here is my RT input shaft after a clutch hub failure. It was cleaned up and a new clutch disk installed. It's been in there for 90k miles and six years. I think your splines look better than mine did.

[Quote and picture from Michael Stock ..I think your splines look better than mine did.]

I sure hope so! I wouldn't have given the above pictured spline much chance of running another 10K miles, much less 90K miles and 6 years. Note also how much debris there was on the transmission face around the spline area. You raise an interesting data point that suggests the transmission spline shaft can appear quite used up yet survive with a new clutch hub. The clutch hub obviously has worn in to be conjugate to the old shaft spline suggesting thatt with proper lube, the hub length isn't the life limiting item. At least that's my opinion, even if it isn't a lot of others....

One item bothers me though - If your first spline hub stripped out so early due to a manufactured misalignment error, why has the second spline hub lasted longer? Might there have been something in the original assembly (presumably at the factory) that misaligned the engine/transmission? Like maybe not using a clutch disk alignment tool at the factory?

Your picture raises a lot of questions. A lot of input shafts have needlessly been replaced.

m_stock10506 said:

I agree with the other opinions given so far. Clean up the shaft, lube it and put a new friction disk on. The photo I'm adding here is my RT input shaft after a clutch hub failure. It was cleaned up and a new clutch disk installed. It's been in there for 90k miles and six years. I think your splines look better than mine did.

View attachment 78499

Click to expand...

Was the drive plate replaced as well when the clutch assy. was replaced?

GSAddict said:

Was the drive plate replaced as well when the clutch assy. was replaced?

Click to expand...

I’m not the original poster. I don’t want to hijack the thread. I posted my comment and photo to give my experience with reuse of a partially worn transmission splines. Just to answer the questions hoping that they help the OP. No, I didn’t replace the rest of the clutch pack. Just the friction disk. The clutch had some shudder as it engaged for a few hundred miles, the new disk bedding into the plate, but it got softer each ride and the clutch is very smooth. I bought this bike used with 48k miles. Had plenty of repairs needed in the first few thousand miles. 207k miles now, three deer and a turkey vulture so I have accepted that the paint and body work is no longer perfect.

m_stock10506 said:

I’m not the original poster. I don’t want to hijack the thread. I posted my comment and photo to give my experience with reuse of a partially worn transmission splines. Just to answer the questions hoping that they help the OP. No, I didn’t replace the rest of the clutch pack. Just the friction disk. The clutch had some shudder as it engaged for a few hundred miles, the new disk bedding into the plate, but it got softer each ride and the clutch is very smooth. I bought this bike used with 48k miles. Had plenty of repairs needed in the first few thousand miles. 207k miles now, three deer and a turkey vulture so I have accepted that the paint and body work is no longer perfect.

Click to expand...

Interesting, information noted.

Thanks all for the replies! At a minimum I should get a clutch pack then I’m thinking. Beemer boneyard has them I see. I did not clean anything when I took the original pic. Not much in the way of debris. For the trans splines I took what I hope are better pics - shown here. For one of them I put some antiseize in the valleys for better contrast.

They are not great, but probably will run as long as you want, with some lube. Considering it took 75,000 miles to get this far they will run that far again with lube.

Would an aftermarket clutch disc with an extended engagement be of benefit here?

BC1100S said:

Would an aftermarket clutch disc with an extended engagement be of benefit here?

Click to expand...

Those are for the 6 speed 1150's / 1100S

PoorUB said:

They are not great, but probably will run as long as you want, with some lube. Considering it took 75,000 miles to get this far they will run that far again with lube.

Click to expand...

Agreed

Thanks all for the feedback! I have leftover sig wurth/ Honda moly (Paul’s formula from awhile back) that I’ll use 50/50. After doing some searching on the forum I think I’ll replace the clutch pack and not just the friction disk. My HES is on its way to GSAddict for a rewire. Figured this was as good a time as any to do that.

jrx222 said:

Thanks all for the feedback! I have leftover sig wurth/ Honda moly (Paul’s formula from awhile back) that I’ll use 50/50.

Click to expand...

Excellent! Good plan.

GSAddict said:

Those are for the 6 speed 1150's / 1100S

Click to expand...

This is why I don't work on other people's motorcycles.