K Bike Monolever Driveshaft Splines

[GlobalRider]

I've never owned a K bike nor have I had any spline issues on any of my R bikes, but I did read Paul Glaves' article in the January '05 issue of the BMWMOA ON.

A co-worker owns a K100RT. He had to replace his driveshaft due to excessive spline wear many years ago. I remember talking about it around the coffee table.

He is also head of failure analysis at our government labs. The driveshaft tested a bit on the soft side in his opinion. But he stated, "better to have the driveshaft wear quicker, than the spines to the rear drive unit", as Paul also mentioned.

I noted from the spline wear photographs on page 75 of that article, that it appeared that some dimensioning or QA may be a problem. That wear pattern is unacceptable. This area isn;t my level of expertise, but it looks like the input shaft splines are too small for the driveshaft splines.

To me, this issue of spline wear, be it driveshaft or transmission input shaft is pure BS in my opinion. The same goes for rear drive unit failures.

Think about it, the components that we have on our bikes are overbuilt as compared to cars when you consider the weight of the vehicle. Our rear drive units are not that much smaller than that of a sub compact car. The driveshafts on our bikes are larger than the rear axle shaft on my Honda CR-V (yeah, I know, it isn't driven all the time).

All this talk about periodic lubrication. The next time my clutch/transmission input shaft splines need lubrication on my car is the next time it'll get a new clutch...at maybe 150,000 miles and I can bet you there will be negligible wear based on my previous experiences.

The only reason we put up with it is because we accept it. And I can't blame individual owners. One voice doesn't have a lot of bark. Why the BMWMOA doesn't get off their rump with the voices of some 50,000 members behind them I'll never know. Maybe a class action suit. But then, think of all the perks they'd miss out on; not getting invited to wine and cheese parties or no new bike press launches in Munich. :stick I'd like to know when the last time a director had a talk with BMW NA about these issues, and what is being done about them.

[PGlaves]

I noted from the spline wear photographs on page 75 of that article, that it appeared that some dimensioning or QA may be a problem. That wear pattern is unacceptable. This area isn;t my level of expertise, but it looks like the input shaft splines are too small for the driveshaft splines.

When you fit a new drive shaft to a new final drive input (pinion) shaft the fit is quite good. Very little play can be felt. However this play increases as the parts wear. By the time the shaft is worn to need replacement there is also some, but less, wear on the input shaft. So on the second shaft you start out with a poorer, and rougher fit. Thus, the second shaft usually won't last as long as the first one. About 3 shafts is all you can wear out before the input shaft is worn enough that fitting a new driveshaft is a waste of money without renewing the spline on the final drive. If properly lubricated the first shaft will last at least 100,000 miles - the second maybe 80,000 miles. You will be lucky to get 40,000 out of the third one because by then the input shaft is rough.

The pictures in the article show the 2nd driveshaft on the 2nd final drive on my K75 at about 350,000 miles on the bike. And it is a pretty loose fit as shown.

Paul Glaves

[GlobalRider]

If properly lubricated the first shaft will last at least 100,000 miles - the second maybe 80,000 miles. You will be lucky to get 40,000 out of the third one because by then the input shaft is rough.

Paul Glaves


Hi Paul,

The shaft on my co-worker's K lasted about 80,000 kilometers (about 50,000 miles) before it needed replacing. His K is a mid 80s (85 or 86). I don't know the specifics, but did the early years have problems with spline hardness?

I never got to see the splines on the rear drive, but I think I remember him saying there was slight wear on them already. He would know in his line of work.

Other local riders had the same issues in the 60,000 miles plus zone. Unacceptable, in my opinion.

There are always certain issues that come to mind because we hear about them often. If that is the case, why doesn't BMW AG address them. Failing to do so only gives the company a bad name. Remember the Iron Butt and rear drive failures? I'm a multi BMW owner and I had trouble keeping a straight face. If I cared, I'd hate to think what non-BMW owners think.

On the airhead Paralever GSes, it was the Valeo starter and driveshaft. I know about those Valeo starters. I pretty much rebuilt the first ones and generated a "how to" article on them. I've been lucky with the driveshaft; my riding style probably helped mine last.

[PGlaves]

The shaft on my co-worker's K lasted about 80,000 kilometers (about 50,000 miles) before it needed replacing. His K is a mid 80s (85 or 86). I don't know the specifics, but did the early years have problems with spline hardness?

Ah, that old "properly lubricated" caveat.

Like it or not (and I don't) monolever K bikes need to have their driveshaft rear splines lubricated about every 20,000 miles for decent life. I do it every 2nd tire when the wheel is off and the final drive easy to pull.

And, I've seen a fairly large number of K bikes with what I consider poor lubrication from the factory - rusty splines at low mileage. On every K bike I've bought - 7 or 8 of them by now - I've pulled the rear end and properly greased the driveshaft regardless of mileage and service record.

I have seen no evidence of a real hardness issue but have seen lots of lack of lubrication. That said, there are metalurgical tricks that could be used to make lubrication almost a moot point so hardness is an issue from a design standpoint, but not necessarily from a QC standpoint.

But, BMW did one thing right! The shaft splines are softer than the pinion shaft splines - which is a good thing. All in all I'm not unhappy with the monolever driveshafts. A chain and sprocket set for my F650 at 14,000 miles cost more than a driveshaft after 100,000 miles for my K75.

[GlobalRider]

But, BMW did one thing right! The shaft splines are softer than the pinion shaft splines - which is a good thing.

All in all I'm not unhappy with the monolever driveshafts. A chain and sprocket set for my F650 at 14,000 miles cost more than a driveshaft after 100,000 miles for my K75.

On the first point, yes he noticed that.

On the second point, being happy that the shaft costs less than a set of sprockets and a chain is exactly why things don't change. Too many accept what is thrown at them. I am only happy I don't have to lube my transmission input shaft in my car every 20,000 miles. Doing so would make owning a car very expensive...probably why we never have to perform that function till we need a clutch replacement at 180,000 or so miles. Owners wouldn't accept it. Considering the harsh environment our cars go through, they are light years ahead when it comes to being maintenance free.

We get what we wish for.

[davel]

Global Rider you make some very good points about excepting a known problem, but its probably to late in the game to get BMW to do anything. I've always lubed the rears and have not had a problem. With the exception of the newer LTs I have not heard of a lot failures with the paralever rears, have you? :dunno

[GlobalRider]

Global Rider you make some very good points about excepting a known problem, but its probably to late in the game to get BMW to do anything. I've always lubed the rears and have not had a problem. With the exception of the newer LTs I have not heard of a lot failures with the paralever rears, have you? :dunno

As for the K Brick engined model, true, as they are being phased out. But that is no reason to accept it in subsequent models.

I remember reading a lot about rear drive failures on the IB. Pretty embarassing for the BMW Roundel, wouldn't you say?

Then there are quite a few rear drive failures on the new R1200 GS. A local rider mentioned coming across quite a few of them just on the way to the rally. I mean, what did we do, invent rear drives last year and we haven't gotten all the bug out? Give me a break!!!

[davel]

Thanks for that information, did not know about the R1200GS problems. I know someone that had a 94 K1100lt that added fill and drain bolts where the rear splines are located and filled it with gear oil not using any spline lube, he put about 10k miles on the bike with that setup with no problems, but shortly after he hit a deer and totaled the bike. Maybe a wet system is the answer. The Paralever was suppose to have fixed the problem, and extend the lube intervals. I agree, BMW has been using some form of this setup since day 1, and should have perfected it by now there is no excuse... :dunno

[GlobalRider]

Thanks for that information, did not know about the R1200GS problems. I know someone that had a 94 K1100lt that added fill and drain bolts where the rear splines are located and filled it with gear oil not using any spline lube, he put about 10k miles on the bike with that setup with no problems, but shortly after he hit a deer and totaled the bike. Maybe a wet system is the answer. The Paralever was suppose to have fixed the problem, and extend the lube intervals. I agree, BMW has been using some form of this setup since day 1, and should have perfected it by now there is no excuse... :dunno

Motorrad Magazine had a write-up on the R1200 GS rear drive failures. Their long term test bike had the rear drive unit replaced as some low mileage.

Well if you ever look at an R100 GS Paralever casting, you'll notice an upper and lower "flat" in the casting near the rear drive. No question BMW was going to machine and thread those for fill and drain plugs. But liability concerns in case the rear boot leaked causing oil to drip onto the rear tire put a stop to that plan. Now on the solid rear drives (older K bikes) that could be done except the rubber damper in the rear shaft being affected by oil might have been another issue.

A wet system was the answer. It was used prior to the Paralever generation. They rarely failed. But BMW wanted to overcome/minimize shaft effect and came out with the Paralever rear, a move backwards in my opinion...so is the single sided swingarm...when did you ever have a rear drive unit bearing failure or driveshaft failure on a 1981 R80 G/S.

Well that is "progress", I guess.

[jdiaz]

I believe that the secondary machining operations on the swingarm, final drive, and transmission housing dictate driveshaft spline wear more than anything else, which is why some bikes are chronic driveshaft eaters and some never have an issue. Its all about tolerancing.

My K75 has 183,000 miles on it, and just got its third driveshaft. The second one was replaced because the u-joint tightened up, but not because the spline was overly worn.

[LTrider]

I've been reading the replys to this thread and read the article in the current BMW ON. Most of the bikes talked about are earlier model K bikes. I have a '97 K11LT. Can I expect the same problems? Should I be lubricating every 20K? My bike just turned 20K on the odometer, and I'm starting to get concerned. I do my own fluid replacement, but a driveshaft and tranny spline lube may be over my head. Any recommendations will be welcomed.

Thanks,

Jim

[GlobalRider]

I have a '97 K11LT. Can I expect the same problems? Should I be lubricating every 20K? My bike just turned 20K on the odometer, and I'm starting to get concerned. I do my own fluid replacement, but a driveshaft and tranny spline lube may be over my head. Any recommendations will be welcomed.

Thanks,
Jim

Well everything points to it being a necessity at regular intervals. Kind of rediculous IMO to have to mess with a so called maintenance-free shaft drive system that often.

Do it if you have the expertise or have it done.

[tommy]

Kind of rediculous IMO to have to mess with a so called maintenance-free shaft drive system that often.
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $$$$$$$$$$$

I agree Alex but some things in this world just don't make since - you know like buying a new Harley & it doesn't come with a battery cover - or back in the early days of HD to solve the problem of lubbing the chain they just put a small hole in the crank case to lube the chain - or spend 20 grand or 25 grand on a new bike & take it in to the dealer for that first 600 service - Ouch - big dollars! i wish they would just hide that 1st service in the cost of the bike & lie to me & tell me it's free - :dunno any more i try to just roll with it - well i don't really but i like to tell myself i do - tommy

[deilenberger]

I've been reading the replys to this thread and read the article in the current BMW ON. Most of the bikes talked about are earlier model K bikes. I have a '97 K11LT. Can I expect the same problems? Should I be lubricating every 20K? My bike just turned 20K on the odometer, and I'm starting to get concerned. I do my own fluid replacement, but a driveshaft and tranny spline lube may be over my head. Any recommendations will be welcomed.

Thanks,

Jim

Driveshaft splines have not been an "issue" on paralever bikes - which your K11 is. The double U joints appear to take the rocking/coupling motion off the splines and they just don't wear like the monolever ones do. If you think about it a bit - the front spline on even a monolever driveshaft never seems to wear. Might just be the U joint next to it that's responsible for that.

The clutch spline problem was also pretty much cleared up by the time your K11 was manufacturered. Check your owners manual to see if there is any specific spline-lube interval - I don't believe there is, or if there is - it's out past 40,000 miles.

Best,

[Hodag]

here's a wrench into the works,
the scheduled maintanence is at 40,000
I was discussing this matter with my dealer, and we were talking about the price of the service. he said he was glad to do it, but I may just wait until the clutch needs replacing. Because if there is excessive wear just replace the drive shaft. When all is said and done it would be cheaper to wait.
thoughts?
mark

[deilenberger]

here's a wrench into the works,
the scheduled maintanence is at 40,000
I was discussing this matter with my dealer, and we were talking about the price of the service. he said he was glad to do it, but I may just wait until the clutch needs replacing. Because if there is excessive wear just replace the drive shaft. When all is said and done it would be cheaper to wait.
thoughts?
mark

Yup. Thoughts:

Your dealer isn't doing you any favor with that advice. A maintained, not-abused clutch on a K bike may well outlast the rider and the rest of the bike. The primary reason for clutch failure is either abuse, or the splines going bad due to lack of lubricant.

In both cases - if the splines on the part you're planning to replace DO go bad, they have also destroyed the splines on the part they mate with.. meaning, when the driveshaft goes bad - the splines on the rear-drive are worn and damaged and will quickly destroy the new driveshaft. Ditto on the clutch.

It's hard for me to imagine the dealer turning this work away unless he doesn't have mechanics competant to do the work - so I'd suggest checking with any other dealer you can get the bike to.

Best,

[Hodag]

I've decided to listen to you, now does anyone have a website that gives the details on doing it. Pictures would be grand also, I'm a fair wrench, but the devil is the details.
mark

[boofer]

I have a DVD from the Sporttouring site.....its done on a RRT though. That and a shop manuel should get you through it, if you have the right tools. That being said, a driveshaft splinelube is way easy and in my opinion the most necessary. Clutch and transmission lube will take you where you probably don't want to be, but the satisfaction of knowing how is a reward in itself.

Waiting for the clutch to need replacing.....worst case senario....would be having to replace tranny input shaft or replace tranny. That is to say, if it hasn't failed by then. The former Could be less expensive in the long run vs having a dealer perform service at regular intervals, you could get lucky.

Tim

[boofer]

Oh, I'm just thirty miles up 47. I can give ya some help if ya get in a bind. Trust me, I was a certified Porsche mechanic in '78, I still actually remember some of the things from the six months of training :thumb

[Hodag]

Oh, I'm just thirty miles up 47. I can give ya some help if ya get in a bind.

I was just thinking the same thing, maybe in the spring I could ride up for an afternoon and learn from an expert (sucking up)? Of course lunch or dinner would be on me.
Mark

[deilenberger]

I've decided to listen to you, now does anyone have a website that gives the details on doing it. Pictures would be grand also, I'm a fair wrench, but the devil is the details.
mark
First place to ALWAYS look:

http://www.ibmwr.org/ktech.shtml

There are several good writeups there - and you DO have a service manual right?

[CustomSarge]

I think the main wear factor of monolever splines is the sliding/galling aspect of its' design. The paralever, having 2 universals on axes with their pivot points, yields minimal spline movement. Same reason for no wear on monolever fronts'. Torque + slide = tough lube task. 'nuff <<<)))

[Hodag]

you DO have a service manual right?

I have a generic k-bike clymer 85-95

any suggestions for a better one?
Mark

[roy]

Look in BMW ON January & February issues Bench wrech section. They have some good pictures of the two different drive types and some generic tips.

Roy

Happy Wrenching

I suspect fear of the unknown is greatest challenge to spline lube.

[deilenberger]

I have a generic k-bike clymer 85-95

any suggestions for a better one?
Mark

I have them all (Factory, Haynes, Clymer) - all have some strengths all have some weaknesses. The factory manual assumes a BMW trained mechanic is doing the job - but - it is very accurate, so I use it for torque settings and things like that. Both Haynes and Clymer have errors in them. Usually not too critical, but they can lead to confusion (one of them - I forget which) has the entire electrical box on early K bikes mislabeled.

With the writeups on IBMWR and your manual, if you are semi-skilled in wrenching you should be able to manage it on your own. Make CERTAIN it is well supported before you take the centerstand off. It's no fun to have it fall over on you.

Best,

[Low Life]

Gudday,

I've been wrenching for quite a while and have come to trust Loctite products over the years. When I first bought my K100LT the first thing I heard was "Lube The Splines". After reading Paul's article I started to search for a product that had a high concentration of molybdenum disulfide. As it turns out Loctite makes a moly paste (part number 51048) that has a 65% concentration. It has a black sticky consistency. We used something very similar on dyno coupling splines back when I worked for Detroit Diesel. I just used this product for the first time this week on the splines of my K bike. Time will tell.

Low Life

[johnnyquest]

I read the tech articles at IBMWR.org and read some in my Clymer manual and I've come to the conclusion that I'm going to take my bike in for the clutch input shaft lube. My local dealer quoted me $200 and another $90 to mount/balance my two new tires. The thing is, I'm just not that great of a mechanic. My friends and I did alot with my bike when I first got it...changed the fork seals, engine oil, coolant, spark plugs....but they have experience working on bikes. The tech articles say it should take about 6 hours or so to do a shaft lube which means it would take me and a friend 10 hours or more. I just don't want to spend an entire weekend and part of a monday trying to do this job. Besides, my income tax refund is on the way :D

So, to stay on topic I'll ask this question: My 1990 K75 has only 21000 miles on it. I'm the 4th owner and the previous owner didn't put alot of miles on it, mainly just kept it in the garage. Will the lube used on the clutch input shaft splines and drive shaft splines dry up over time? Or since these are sealed systems will the lube hold up fairly well? I guess I'm afraid of what the techs will tell me when they tear into my bike in a couple of weeks. I hope I won't regret putting 2000 miles on this bike after buying it without lubing the driveshaft and clutch input shaft.....

JQ

[boofer]

Mr. Quest, sir....the proper grease is nasty stuff indeed ! It should still be good. IMHO a driveshaft lube would be in order, but I would wait till at least 30k to do the tranny input splines. When you do the driveshaft (if) you will be able to better determine the state of the grease.

BTW from BMW it's about $55 a tube (my dealer offered me some in a dixiecup free) but I needed some for my shop anyway. Wear gloves, it's a pisser to wash off !!

Tim

[Kenny2]

.... but I would wait till at least 30k to do the tranny input splines. ...Tim

My R1150RT (2002) with 28,965 miles is in the shop being re-built. transmission cover was mis-milled, causing improper alignment of the input shaft to the clutch. The splines and the clutch are toasted!!!! Left me on the side of the road as I was riding to DVD. Also, check the slave clutch cylinder, my was leaking and corroding.

Oh yes, This is the extended warranty. ALL paid for by the Company. :twirl