A couple of days ago, while riding home from work I developed a sudden problem with my clutch. My bike's a 1989 K100RT with 92K miles. Since purchasing it in March, I haven't had any problems at all.

I stopped at a stop sign like normal, no strange noises. But when I shifted into 1st, the clutch would not release so the bike would move. I can shift into any gear, including neutral, but releasing the clutch handle does not allow the bike to move. Letting the handle out and revving the engine, the upper gears sound like something is "bouncing" across the top of the gear teeth, but not engaging. I still have tension in the clutch handle like normal, so I don't think the clutch cable broke.

With tomorrow being Saturday, I'll have time to work on it, but know more about cars, especially old ones, than bikes. I don't want to just start taking it apart if I can help it. But I also don't know what it's likely to be. The shop manual indicates that the clutch can be accessed without removing the engine or trans, but I don't know how (yet).

Can anyone suggest the probable problem? And/or things to try, hopefully without taking too much apart? I'd appreciate any advice I can get. Thanks!

Sounds to me like the spline in the center of the clutch is cactus. It's a known problem with the Ks especially if the spline has not been lubricated.
The other thing it could be is the spline on the rear end of the drive shaft and for the same reason.
Either way it entails removing the rear drive and possibly the gearbox.
Hint:- If you go to the introduction thread and tell us about yourself and of course the bike you will get access to lots of info on the downloads page after a few more posts.

Hello, could be anything, splines, pushod, clutch tensioner plate, but if you lucky could be something really simple and easy fix. Check the rear clutch lever, maybe you just lost the bolt for adjusting preload of lever, so the lever doesnt make pressure. (6 mm bolt with adjusting nut - 13 mm)

Regards

That is exactly how mine felt when I did the clutch splines. Also it is exactly how it felt when I did the Final drive splines. so presuming you still have clutch pressure on your clutch handle or lever. the best way to confirm is to put bike on centre stand and put it in gear then turn rear wheel. listening without the engine running you will hear which splines are turning over each other. That is either the rear ones or the clutch ones. Then you can remove the rear final drive and try turning the drive shaft inside the swingarm if it wont turn with vicegrips without turning the engine over, then a fuller inspection of the drive shaft and the Final Drive (best known in here as the F/D) will be needed as it may be the drive shaft needs replacing. Others have posted pics of their inspections in this "engine transmittion section" just snoop about you will find them

K75cster wrote:That is exactly how mine felt when I did the clutch splines. Also it is exactly how it felt when I did the Final drive splines. so presuming you still have clutch pressure on your clutch handle or lever. the best way to confirm is to put bike on centre stand and put it in gear then turn rear wheel. listening without the engine running you will hear which splines are turning over each other. That is either the rear ones or the clutch ones. Then you can remove the rear final drive and try turning the drive shaft inside the swingarm if it wont turn with vicegrips without turning the engine over, then a fuller inspection of the drive shaft and the Final Drive (best known in here as the F/D) will be needed as it may be the drive shaft needs replacing. Others have posted pics of their inspections in this "engine transmittion section" just snoop about you will find them

OK, I did some checking and the noise is definately coming from inside the clutch, not the rear end. So I guess I get to disassemble about 1/2 of the bike!

Next question: Obviously, the labor is going to be the expensive part of this repair, not the parts. Does anyone have a ballpark idea of what this would run to have a shop do it? Am I looking at $500? $1000? More? I don't think it's going to be $100, but I'm guessing somewhere between $100 & $1000. If more than that, the bike could be worth more in parts rather than trying to repair it. Or it may become a winter project, based upon my lack of time to work on it.

Sounds like clutch plate splines that have stripped. I think you are goind to need a new clutch plate and while you are about it let them do a spline lube on all the splines if they are OK. Cost wise it is hard to say but going on aproximate cost in S.A and converting to US$ I would estimate +- US $650

For a competent bike mechanic it should be a 4-5 hour job, however if and it is quite probable the spline on the input shaft to the transmission is damaged it well could be a extra 3-4 hours plus the cost of a good used shaft.
cost if shaft is damaged could well be in excess of $1000 and without a shaft around $600 plus any extra parts.
You would be best to do the job yourself and use a used transmission, the cost would be quite a bit lower as most of the money is for labor which even a home mechanic would find a straight forward job. A used transmission would cost around $200 for a good low mile one.

If you work on old cars, you will be amazed by how easy it is to remove the clutch.
The gear box has to be removed but this is a one hour job.
Before spending a lot of money on labor, you may want to watch the following videos about the procedure.
Also, check This post.
With a bit of research on the forum, you can find the whole process with lot of pictures.

CF

Thank you everyone for the good, courteous advice! It looks like I will be doing this myself, but I won't be able to start working on it for 2 weeks - prior obligations. I don't want to take it apaer and let it sit for too long, at my age, I can forget where things go back together!

It feels like the splines stripping is probably the problem, but is that likely with no previous indication of a problem? No noise, vibration or anything; just refused to move at a stop sign where I stopped normally???

I just had another idea about this. The only thing I really don't like about this bike (other than it's not a H-D) is that 4th & 5th gears are real close together. The national speed limit was 55 in 1989, so there was no need for 5th to be overdrive, but it would be really nice now. If I'm going to change the trans, maybe I should consider changing to a trans with overdrive for better mileage??? Any ideas what models and years of trans could be used for a direct swap, without major modifications being necessary?

mtype1931 wrote:Thank you everyone for the good, courteous advice! It looks like I will be doing this myself, but I won't be able to start working on it for 2 weeks - prior obligations. I don't want to take it apaer and let it sit for too long, at my age, I can forget where things go back together!

It feels like the splines stripping is probably the problem, but is that likely with no previous indication of a problem? No noise, vibration or anything; just refused to move at a stop sign where I stopped normally???

Don't worry... If you have any problem, we will help you. Few of us have experience about removing the gear box.
Every step is well documented on the forum. Please check my first rebuilt page as their are plenty of pictures.

CF

The gear ratios are the same right through the range that use that type of gearbox, the only difference being in the K75 where the 5th gear was even closer to 4th.
you will get a small advantage by using a rear drive from an RS. RT 2.91-1 RS 2.81-1 but that is your options.

As rickG has stated most people change the final drive to lower the rpm. I read somewhere that the 1100,s have a 1.61: 5th gear and we have a 1.67:1 5th gear, but really that's got to be 60rpm difference????. who would notice. When my clutch went south I took things apart and took the geabox and clutch plate to the BMW bike shop for them to discern what needed doing, conclusion? They replaced the input shaft also. Cant remember the cost as it was 1998 or there abouts. as the teenagers I cart about would say "its so lst century" cheers

The ratios are correct but the K75 has 1.67 and the K100/K1100 has 1.61

I appreciate everyone's input, but it turned out to be something unexpected. The lower end of the drive shaft came apart. The sleeve with the internal splines split open. I was able to find a replacement one on eBay for only $75.00 and I'm completing reassembly now.

I have about another hour to go and I should be back on the road, just in time for the weather to turn cold here in Wisconsin. ButI should still be able to get some additional riding time yet this year. My total repair cost turned out to be under $100.00 US and only about 8 hours of time total. I'm REAL thankful I didn't have to remove the trans and clutch after all!

Did you take any photos of what you found to be the problem? I'm sure everyone would like to see it. Good to hear that it was easy and inexpensive to fix.

mtype1931 wrote:I appreciate everyone's input, but it turned out to be something unexpected. The lower end of the drive shaft came apart. The sleeve with the internal splines split open. I was able to find a replacement one on eBay for only $75.00 and I'm completing reassembly now.

I have about another hour to go and I should be back on the road, just in time for the weather to turn cold here in Wisconsin. ButI should still be able to get some additional riding time yet this year. My total repair cost turned out to be under $100.00 US and only about 8 hours of time total. I'm REAL thankful I didn't have to remove the trans and clutch after all!

That would be very interesting to see especially from a metauurgist point.
Would you put up some pics of it please. I would even like to see it in the flesh as that is one of the last things I would expect to happen.
Thinking about without seeing it would almost have to be a fault in the metal.

mtype1931 wrote:I just had another idea about this. The only thing I really don't like about this bike (other than it's not a H-D) is that 4th & 5th gears are real close together. The national speed limit was 55 in 1989, so there was no need for 5th to be overdrive, but it would be really nice now. If I'm going to change the trans, maybe I should consider changing to a trans with overdrive for better mileage??? Any ideas what models and years of trans could be used for a direct swap, without major modifications being necessary?

(other than its not a H-D) ?????? Then why ride a BMW when one lives in the land of the H-D? Someone asked me once what was not to like about a H-D and I replied that nothing, other than the Poor Handling, Dreadful Vibration,Ordinary Braking, and Questionable Reliability, H-Ds are IMHO a pretty ordinary Motorcycle. Certainly any comparison with a BM would have to be attempted with more than a little National Pride. I must say that in the early days of motorcycles they were a force to be reckoned with but I am afraid that they stopped progressing in about 1950 and oddly enough the only modern concept V-ROD ? is it seems disliked intensely by the true? H-D enthusiast . Go Figure.
Regards (tongue in cheek?) Dennis.

STEVE1959 wrote:Did you take any photos of what you found to be the problem? I'm sure everyone would like to see it. Good to hear that it was easy and inexpensive to fix.

+1 steve ....would love to see the fault and the fix ...!

mtype1931 wrote:I just had another idea about this. The only thing I really don't like about this bike (other than it's not a H-D) is that 4th & 5th gears are real close together. The national speed limit was 55 in 1989, so there was no need for 5th to be overdrive, but it would be really nice now. If I'm going to change the trans, maybe I should consider changing to a trans with overdrive for better mileage??? Any ideas what models and years of trans could be used for a direct swap, without major modifications being necessary?

Change the rear drive ratio as there are no options for a different gearbox.

Attached is a photo of the broken drive shaft that was requested (if I can figure out how to attach it).

With regard to the criticism of my H-D preference, I've always been a H-D guy. I've only had a Sportster so far, but am hoping to upgrade in a couple of years. I had to sell my Sporty a few years ago due to financial hardships. I tried to get one this Spring, but was not able to due to the continuance of financial difficulties. The BMW was a compromise. I wanted a bike to save money ($4 gas) and I will NEVER buy a Jap bike (or car, or anything else that I can avoid). With my lifetime hatred for any oriental products, I would never live it down if anyone that knows me ever saw me on a Jap bike. But I didn't get too much grief for riding the BMW.

Well, it doesn't look like it attached. Any advice on how to attach the photo?

have a look here

http://k100rt.aforumfree.com/t998-posting-pictures-and-movies

Well, I don't seem to be able to get it to load. If someone wants to e-mail me at xxxxxxx@msn.com I can e-mail it. Then that person may be able to load it so the public can see it. Sorry.

Email sent Might be a good idea to remove that email address, the bots get a hold of it and will spam your mailbox

Here is the photo of the broken driveshaft

Holy snappin duck shit batman that is shattered and there is AFAIK only one cause for that. Bad heat treatment at time of manufacture has caused a brittle molecular structure.
Has anyone else seen this happen.

I appreciate the help loading the photo. it's strange that a manufacturing defect would manifest itself now. The bike has 92,000 miles on it. I would have thought it would have come apart much sooner if it was poor heat treatment. But who knows....

My thoughts exactly Rick never seen one do that before I have seen twisted shafts but that was high powered drag cars.
Now how does one claim warranty on that as its obvious its a manufacturing fault
( send it to TWB and let him deal with it ? ) Does make you wonder what caused it tho FD seizing or maybe gearbox
Knowing Inge he will probably correct me with specific torque required to do that and what lead to the destruction ( he's a walking encyclopaedia anything K )

Cheers Tony

Mtype1931 Never seen that before amazing, I like HD's as well the sporties are good fodder spoke to a bloke who put shovel heads on his and he had 1200cc's before HD did it, I;d say the road king has the look, have liked the look since they came out. My K75 730 tripple has the triumph t150 sound and I like that. I like these early K series looks too

Toto_jp wrote:My thoughts exactly Rick never seen one do that before I have seen twisted shafts but that was high powered drag cars.
Now how does one claim warranty on that as its obvious its a manufacturing fault
( send it to TWB and let him deal with it ? ) Does make you wonder what caused it tho FD seizing or maybe gearbox
Knowing Inge he will probably correct me with specific torque required to do that and what lead to the destruction ( he's a walking encyclopaedia anything K )

Cheers Tony

or some dimwit ...just banged the crap out of the furule that does the interface to the pinion to take up the slack of a dry spline ....causing a fracture that let go "bigtime" some time latter (highly likely )

Charlie is that even possible? could imagine a big vice or pipe bender type bottle jack sort of bearing puterina maybe one of them. When my F/D let go I thought I might be able to get to work for the rest of the week by using needle bearings to fill the gap between the two splines and make do. but ended up just pinching the car and driving down, took the lot over to the bmw bike shop for a what now session at lunch time. wonder what they would have made of such a scheme