tranny input shaft

There is no need for longer shaft AND modified clutch hub. It is either or situation. The rest of the parts are on a need to change basis and I would go as far as saying leave the input shaft alone even if it is worn. Since there is no longer shaft there is only one option. With a modified clutch hub it should be enough surface to be OK.


I currently have 5 mm spacer added to my original clutch that had a little wear on the clutch hub installed in the bike. I have little over 500 miles on it. Since I didn't have rivets I bolted the hub with 12.9 hardness 5mm bolts with lock washers and red locktite on the other end. I checked it thorough the starter hole a couple of times and it looks OK. I ordered new clutch plate that is disassembled and waiting on the next spacer and rivets to move on to phase two. Unfortunately I didn't take any pictures the first time but I will on the next removal. I have been riding it hard, probably harder than I would normally just to see if it can handle it. I think for the people that the input shaft is far gone already this is the only way to go. As I said in my case shaft was OK with no signs of wear but discolored at the failure point

There is also info floating around that if the splines are going to fail because of misalignment then they will do it within 30k miles. If they fail later then it is because of the lack of lubrication. I think this is also incorrect. I think that overall population of failures is probably normally distributed with peak at 30k but higher and lower mileage bikes fail because of the same root cause (whatever that root cause is).
IMHO it is highly unlikely to have 3-4 different root causes result in the same failure. It is usually one main driver and the rest add to the "randomness" of time in service and mileage chart of failures. Some never fail. It is also very unlikely to have a part with 100% failure rate despite all the other factors.

Another piece of info is that new clutches are made in Slovakia. Original was made in Germany. Supplier will make production and service parts on the same equipment at the same time, in order to minimize costs. Then the line is shut down and on to the next project.
The fact that the new clutch plate is made in Slovakia means that original stock was exhausted and equipment was reassembled in Slovakia, recently (labor costs). I have also read that sometime last year there was shortage of clutch plates for 1150's, probably when they ran out of the original stock and decided to reopen the production but in Slovakia. This means that original estimates of clutches needed for service parts was too low (for whatever reason), which means that failure rate is higher. Just adding facts together.

Still a lot of speculation which is why I decided to do something and not just talk, probably Chris Hariss logic also.

by the way here is my test mule.

PGlaves said:

Again - hard to argue with, except that longer shafts and longer hubs together cost $1,500 plus the labor to install the shaft in a transmission ($500 to $1,500 depending on what else is done while you are in there) plus the labor to take the transmission out and put it back in (another $1,000 to $1,500 unless you do it yourself). So the simple "fix the obvious" sets a person back from $1,500 to $4,500 and doesn't address at all the possibility the clutch housing is bent, or the cases are misaligned, and the possibility that those other clutch parts ought to be replaced too.

A person could get $6,000 into a fix for a $5,000 bike in a heartbeat!

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I think our discussion is mostly focused on people doing their own work so as long as parts costs are kept in check we win . For the rest of the "wrench challenged" population , I am with you 100% as far as the costs go.

happy wanderer said:

The parts themselves are probably pretty uniform as they are made by machines. There is one other major variable however and it is the human assembler and the human riders. I've always thought the way a bike is ridden might be a big factor here too.

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Even-though I've only put 6k of the 38k on the bike I've often wondered if my very conservative riding style may have contributed to shaft/hub failure. I see several posts where folks are saying these bikes like higher rpm's, while I was content at 3200-3500. Could shifting at these rpms be placing more stress on the affected components? What is the ideal way to shift?..blip the throttle prior to clutch disengagement?

While it is possible that riding style contributes to the failure that part is not really an issue for you right now since your main priority is fixing the bike. Correct way to upshift is to preload the shifter with your foot, release the throttle slightly and suddenly, shift up and get on the throttle at the same time. Done correctly you don't need the clutch at all. Here is a good video on youtube. there are other videos also but the principle is the same. downshift is a little different but you can also find good videos online.

http://www.youtube.com/watch?v=WZMPJor1jXA

I don't think that low rpm cruising is the cause of failures. My two cents.

I ride conservatively (I'm 75) & my R1100RT splines were pristine at 25K miles. Relubed and reassembled. Hope I didn't screw it up by taking it apart.

I just did a spline lube on my 1100rt at 87000 miles. The shaft was dry although there was no noticable wear. I lubed it up and reassembled.

snookers said:

I just did a spline lube on my 1100rt at 87000 miles. The shaft was dry although there was no noticable wear. I lubed it up and reassembled.

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Did you have a chance to check on the clutch plate splines since the wear start there before it shows up on the input shaft.

cele0001 said:

... I have been riding it hard, probably harder than I would normally just to see if it can handle it. I think for the people that the input shaft is far gone already this is the only way to go. As I said in my case shaft was OK with no signs of wear but discolored at the failure point.
...

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The shape of the wear pattern and the color you mention seem somewhat diagnostic. What thoughts are there on when the material there is being heated more than the surrounding metal?
RB

I am thinking that before the actual failure start there is weakening of the material due to heating.
My other random thoughts.

Clutch splines and hub connection has to be kept somewhat "lose" to allow sliding of clutch plate unlike a fixed spline hub connection where you are dealing with almost interference fit.

The shape of the wear pattern suggests that the clutch hub is slowly tilting on each impact,(because it must be slightly lose), more and more as the time goes. It is flexible enough to allow this movement and return to normal position when the things settle.Now, if there was full engagement this tilt would be met on the opposite side by clutch hub meeting the spline, (on the engine side) but since this second point of contact is missing things get out of control. Once the initial play is created it is only a matter of time.
I will try to get some pictures but I hope I am making sense. Sometimes the more you think about lines and angles the less sense everything makes.

Although a differential hardness has been advanced as a reason for the inboard wear on the shaft, your explanation plus the heated zone makes sense too. Looking at it, it's like the end of the clutch hub is a cutting tool, wearing into the spline where the end makes contact. And digging into it quite effectively!

cele0001 said:

Did you have a chance to check on the clutch plate splines since the wear start there before it shows up on the input shaft.

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Yes I did, and as the pics below show, there is no appreciable amount of wear on those splines.









I failed to take a pic of the tranny input shaft splines before I applied some HONDALUBE, although, within the pic of same, you can make out the splines and the good shape they are in.






I must admit, that with all the talk on the subject of tranny spline wear, I was wondering what I may find when the bike was disassembled. Considering what others have found, I am fortunate.

Here is a better pic of the input shaft, with the Hondalube already applied

That is very nice indeed. Put it together and enjoy.
Yours is 1100. I am assuming that it is not hydraulically actuated.
I am not sure if 1100 suffer from this issue or not.

EDIT: I also see special long guides installed. Looks like a professional job there.

cele0001 said:

Yours is 1100. I am assuming that it is not hydraulically actuated.
I am not sure if 1100 suffer from this issue or not.

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If "this issue" means the less than fully engaged spline length, no. If "this issue" means stripped splines then yes. The possibility of a bent flywheel, misaligned shafts, rust, and the lack of lubrication affect 1100s as much as they affect 1150s I think. Of course, classic K bikes and Airheads also suffer from dry, rusty, worn splines too.

The guide pins I believe you are referring to are 8mm X100 mm allen head cap screws where the hex head has been cut off and the cut ends rounded

So 5 speed transmissions have full spline engagement?

snookers said:

The guide pins I believe you are referring to are 8mm X100 mm allen head cap screws where the hex head has been cut off and the cut ends rounded

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I know but it sounds better when you say "special tool"

PGlaves said:

If "this issue" means the less than fully engaged spline length, no. If "this issue" means stripped splines then yes. The possibility of a bent flywheel, misaligned shafts, rust, and the lack of lubrication affect 1100s as much as they affect 1150s I think. Of course, classic K bikes and Airheads also suffer from dry, rusty, worn splines too.

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Sorry for being vague, By "this issue" I meant incomplete spline engagement.

Here is some eye candy.
I love the smell of stainless steel in the morning.