Hi all,

Out for a ride enjoying the smoother running of newly replaced air intake and cleaned up throttle bodies and something went in the final drive. Feels like something got loose and now teeth aren't lining up. Whole thing goes about 3 feet, starts knocking and then completely siezes like you're trying to roll it in first gear.

Going to start stripping it down.

Any ideas would as always be greatly appreciated.

Just found Crazy Frogs Tutorial which probably explains it:

http://k100rt.aforumfree.com/t1059-bmw-k75-k100-final-drive-shaft-spline-failure-causes

Nice one BMW........

Good luck with it mate
after reading a few horror stories I got brave and pulled mine apart last year and think I was just in time. Bone dry and wearing badly.
There are a few posts on getting a new set of teeth welded on the shaft, or tractor (smaller lawn mower types)
sellers might have a replacement from PTO drive shafts.
RT

Mine had a big lie down last year and I pulled it apart and replaced the two bearings. It's not a difficult job to do. If I can do it, anyone can. It's more than likely going to be a bearing. The actual crown and pinion etc are pretty robust. Am attaching a pic or two.
Sean.

PS. Don't forget to support your swingarm and shaft when you remove the final drive.

Thanks for the reply advice, wishes of good luck and helpful pics. The crunching sounds like its coming from further up the shaft..the final drive actually sounds alright. Wont be able to tell unitl i find a 11mm hex socket to get it off. A bizare size which I am finding it difficult to source locally.

oh? uni joint break up ?...could be

http://advrider.com/forums/showthread.php?t=691571 also found this which is a useful resource for people. When thinking about lubricating splines.

charlie99 wrote:oh? uni joint break up ?...could be

Sounds like that might be the case Charlie....unfortunateky my x-ray vision is not working. Oh for an 11mm hex socket. If it is the UJ i presume a shaft replacment is the only cure.

maybe not ....im sure there are small engineering shops that could source and refit ...just a smaller size than standard auto uses

Motorworks also sell the shaft in two section £100 and £120 respectively so not the end of the world. Will let you know when I pull it apart> Also ordered some moly and suitable chatised myself. Not feeling the 'Zen' at the moment.

Pity you've bought the moly, I have a small stock of Staburags from the German boys over on Flyingbrick which i'm selling at a low price, if you or anyone else is interested pm me.

giles4060 wrote:Thanks for the reply advice, wishes of good luck and helpful pics. The crunching sounds like its coming from further up the shaft..the final drive actually sounds alright. Wont be able to tell unitl i find a 11mm hex socket to get it off. A bizare size which I am finding it difficult to source locally.

Where do you use an 11mm socket?

When reading this thread it seems to be that we speak about a paralever, which got a 11mm allen at the pivot bolts before the crud in the key hole is removed.

When one using a 11mm allen key on this, it`s often ends out with a nice perfectly round allen key hole.

Needless to say....the key hole is 12mm.

A timely reminder is needed to include your model and year of the bike in question in your signature.

Well-meaning members could give you a bum steer (wrong information) because they make assumptions to the bike you are talking about.

Thus endeth the lesson...

blakey wrote:A timely reminder is needed to include your model and year of the bike in question in your signature.

Well-meaning members could give you a bum steer (wrong information) because they make assumptions to the bike you are talking about.

Thus endeth the lesson...

Could we continue the lesson......how do I create a signature?

K100 RS 1991
R80 GS 1990

I'll PM you.

Inge K. wrote:When reading this thread it seems to be that we speak about a paralever, which got a 11mm allen at the pivot bolts before the crud in the key hole is removed.

When one using a 11mm allen key on this, it`s often ends out with a nice perfectly round allen key hole.

Needless to say....the key hole is 12mm.

Clearly not needless to say....as you said it.....and i needed to listen. As always you are right.

Now all i need is super human strength and a bar for the end of my ratchet....of which I have neither. Would it be useful to heat it? And another stupid question I assume this is a normal thread and it's anti clockwise to undo? Is so is there a trick to prevent the shaft having to go through its travel before you can apply force?

Necessity is the mother of.........it seems an old steel mountain bike seat stem and a wife standing on the swing arm to keep it at bay works quite well........funny this technique is not in the Clymer?

Very relieved the splines are all fine............however the UJ is in two pieces. One in my hand the other still on the output shaft. I belive the UJ is probably the cheaper and less troublesome to repair....or at least replace. A call to Motorworks in the morning.

Suggestions on jobs to do while i am here would be appreciated. I beleive the gear indicator switch is around these parts and mine seems to have a few issues.

But first the oven cleaner!

captaink wrote::pale:

Sounds familiar, this was mine.

ew.php?i=9&u=16685389][/url]

Mine went crunch, doing 70mph overtaking at 06:05am

Have a look at the clutch push rod boot, it might be perishing, also bearings may need replacing on shaft arm?
Somebody else might shed some light on the gear indicator issue.

When mounting the parts back together, be shure that the clip at the FD
end snaps into the groove.
If not it often ends up like this, a damaged rear UJ.

Have a look at this, about a tool for tightening the lock nut, after the preload for the bearings is set.

Thanks chaps. All good information. Would be lost without this forum.

Inge K. wrote:When mounting the parts back together, be shure that the clip at the FD
end snaps into the groove.
If not it often ends up like this, a damaged rear UJ.

I came to this conclusion as well. Its not always the reason but I have seen a few get destroyed within a short time of doing a spline lube.

How easily should the shaft drive come apart.....mine seem welded together?

Rear part of the driveshaft, or driveshaft to gearbox?

If it`s the rear part of the driveshaft, it`s another indicator that clip at the FD end haven`t been in the groove.
It should be easy to split, since this is the sliding part on a paralever....which should have been well lubricated.

I would suggest that you try a slide hammer with a hook, keep the driveshaft in a straight line as possible.

It could be that it then comes loose at the gearbox end instead.....then you could put it in a wise.

Be shure to phase the driveshaft correctly, when remounting.

Thanks Inge.

Good advice about the reassembling the shaft....not something I had initailly considered. New shaft bits have arrived. Just waiting for the Moly grease. While I am here I should probably address some other issues:

Could anyone confirm:

1. You do not have to dissassemble the clutch to lube clutch splines.....just remover the Transmisson.
   
2. Oil that I found in the swing arm is likely to be a leaky output seal in a previous thread it has been suggested this is from "the gearbox output shaft seal or the final drive input shaft seal. Oil will collect in the final drive shaft tunnel, which you won't notice unless the ballow rubber between gearbox and tunnel is gone".
   So looking at the rear of the bike transmission in place I pressume the output shaft seal is the one around the the splines that the shaft fits on to and this is going to be Gear oil from the gear box
   
3. Can that output seal be removed without spliting the transnission case.
   

Sorry feeling slightly out of my depth and asking stupid questions so as not to make a stupid mistake.

giles4060 wrote:Thanks Inge.

Good advice about the reassembling the shaft....not something I had initailly considered. New shaft bits have arrived. Just waiting for the Moly grease. While I am here I should probably address some other issues:

Could anyone confirm:

1. You do not have to dissassemble the clutch to lube clutch splines.....just remover the Transmisson.
   Just remove the gearbox
   
2. Oil that I found in the swing arm is likely to be a leaky output seal in a previous thread it has been suggested this is from "the gearbox output shaft seal or the final drive input shaft seal. Oil will collect in the final drive shaft tunnel, which you won't notice unless the ballow rubber between gearbox and tunnel is gone".
   So looking at the rear of the bike transmission in place I pressume the output shaft seal is the one around the the splines that the shaft fits on to and this is going to be Gear oil from the gear box Yes
   
3. Can that output seal be removed without spliting the transnission case. Yes
   

Sorry feeling slightly out of my depth and asking stupid questions so as not to make a stupid mistake.

No such thing as a stupid question. Its better to ask questions than make mistakes as mistakes are costly questions are free.

Thank you. Will probable leave the seal this time as I am happy to keep a close eye on the gear box oil and do not have much time at the moment. Can the seal be removed with transmission in situ? Drilling a couple of holes in the meatl casing (of the seal) and using a couple of self taping screws to pull it?

Be awkward to do but it is accessible and quicker than removing the gearbox.

Anyone have any experience of removing the transmission without removing exhaust system. Cylind head bolts look very rounded and could do without the extra grief a time at the moment? Should exhaust be heated for removal of nuts?

giles4060 wrote:Anyone have any experience of removing the transmission without removing exhaust system. Cylind head bolts look very rounded and could do without the extra grief a time at the moment? Should exhaust be heated for removal of nuts?

Hi there, I´ve done it removing only the silencer, dont know if can be done in your´s.
Best regards
JAP

Hi there, I´ve done it removing only the silencer, dont know if can be done in your´s.
Best regards
JAP[/quote]



Single unit unfortunately.

Yes, can be done, slide the box back on threaded bar.

Could be a tricky one, never tried.............
What I have in mind is that the part of the exhaust under the gearbox could get in conflict with the flange at bottom front on the gearbox.

It could be smart to support the rear end of the exhauster with a strap from the frame.
And remove the clutch pushrod before pulling the gearbox.

Thanks for all your help. I think i would have problems even getting the clutch lever / push rod assembly off as the is very little clearance on the collection box.

I havedecided (slightly beaten and deflated) to leave the clutch spline lube as I would rather do a proper job and not risk damaging anything as a result of lack of clearance for the transmisson removal.

I have all the bits for the shaft replacement which is where this started so lets get that done so I can use the bike. I will then takle the exhaust at a later date and then get the clutch and output seal done. Resisting summit fever I am instead going to tidy my work space have a beer and to the shaft on Friday.

Over and out.

ungaas wrote:Yes, can be done, slide the box back on threaded bar.

I did my first spline that way, is difficult to appreciate the clutch plate teeth condition, don't say removing the old grease and properly apply the new. I preffer to take down the gear box so you can check and clean everything on the way.
Hope this helps
Best regards
JAP

Could i just talk this through for comment...

The transmission could possible be slid back on a bar to prevent complete removal but allow access to clutch splines. I assume the bar would need to be a simialr thickness to transmission out put shaft and suspended may be from the bike frame so it is in line with the output shaft. Then the transmission can be slide back and the weight supported half on output shaft and half on bar.

or

Bar set up under the transmission box and the transmission slid back onto it.

How much clearence would be required to access clutch splines?

Still not sure if the is enough clearance between the exhaust collection box and the transmission on the RS16 valve 1991.If anyone has downd thi on this model comments would be appreciate.

As for the exhaust headers I think I am going to have to cut through the stud to get them out. Fun and games.

If the nuts on the exhaust headers are rounded or corroded away, you can remove them with a small nut splitter. I had to do it a couple of years ago on a K75.

Avenger GT wrote:If the nuts on the exhaust headers are rounded or corroded away, you can remove them with a small nut splitter. I had to do it a couple of years ago on a K75.

A nut splitter. Brilliant I never new such a thing existed....every day is a school day. Thank you.

Sounds like you're having a right nightmare! Also sounds familiar though, my K100RS (1989) did exactly the same to me last Tuesday, in London, in the rain and with no recovery service (only road side assistance). Ended up leaving the bike in London for two days (unlocked), then hired a trailer (£30!) and went and got it on the friday evening (got home at 03:30hrs). Made some enquiries regarding cost and the figures were ridiculous, so I took it aprt myself to search for clues. I thought it was the clutch, then I thought the final drive, but turned out to be the shaft. I rang motorworks (very helpfull), but were too expensive - £75 cheapest, plus carriage. I then rang Gerry in Lutterworth. I knew he was/is breaking a K75 (1986) and knew the shafts (etc) were the same. Bingo! he still had the shaft, so off I went and took it (and the swing arm) of what remians of his K75. Gerry only wanted a tenner, but I gave him twenty quid, and still felt like I was robbing him. Back home, I fiited the shaft and swing arm (with only minimal fuss), and put the whole thing back together. The next day I went back to London (right in the city) to make another delivery (I'm a courier). I collected at 15:45 from Northampton, went into the city, and back out again, then called in at London Gateway Services to use el boggo, I arrived at the services at 17:50! Though I was a bit worried my bike might fall to bits (I did all the work remember, and I aint no mechanic man!), the bike was fine - any worries left me as I weaved my way in and out of the city. That was on Monday. On Tuesday I went to Sandy in Bedfordshire for a collection going to Birmingham. I made the collection, and made my way out of the car park.......BANG! the clutch cable snapped $%&^! Eventually I got the RAC out and they managed a temporary fix at the road side (as expected - I tried to do it but couldn't get any tension in the cable). I managed to get the bike home only using the clutch to set off and come down the gear box. They said the clutch was very heavy (which caused the problem). When I got home I couldn't get the bike out of gear! The clutch has now given up! And so have I!! The K is going! It is just costing me money (like over a grand in earnings this week!) So, who wants a 1989 BMW K100RS in very good condition, with 3 months tax and 8 months MOT, two brand new tyres (Pirelli Sports Demon), a newly replaced shaft, but with a dodgy clutch? 500 quid and it's yours! Thanks. Terry

Gerry can be contacted on 07977850040

Giles before you go cutting any studs have a look at My resto thread. I ran into some problems with broken studs and it took a fair bit of awkward work to recover the situation. A small nut splitter would have served me better methinks!

88KE

If you are using it to make your living you have the wrong bike. Its 20 years old at least and WILL give you problems if you try to do the sort of distances that are expected every day.
If you are going to use a bike to do that sort of work get one that is new and has a 3 year warranty and trade it every 3 years. that way your costs are fixed and you are unlikely to have major problems if serviced and maintained properly.
Use the K for recreation and the occasional blast to clear the cobwebs.
I have a friend here who has a 1986 K75c and when the starter button finally gave up and the bike could not be started she was saying THIS IS A BMW IT"S SUPPOSED TO BE RELIABLE.
Well yes it is but one starter button in 26 years is a good track record. Most other brands especially the Japaneese ones are well and truely in the wrecking yard by now.
Terry they are good bikes but don't expect to be able to do courier work on a 20 year old bike regardless of what brand it is.

Rick G wrote:If you are using it to make your living you have the wrong bike. Its 20 years old at least and WILL give you problems if you try to do the sort of distances that are expected every day.
If you are going to use a bike to do that sort of work get one that is new and has a 3 year warranty and trade it every 3 years. that way your costs are fixed and you are unlikely to have major problems if serviced and maintained properly.
Use the K for recreation and the occasional blast to clear the cobwebs.
I have a friend here who has a 1986 K75c and when the starter button finally gave up and the bike could not be started she was saying THIS IS A BMW IT"S SUPPOSED TO BE RELIABLE.
Well yes it is but one starter button in 26 years is a good track record. Most other brands especially the Japaneese ones are well and truely in the wrecking yard by now.
Terry they are good bikes but don't expect to be able to do courier work on a 20 year old bike regardless of what brand it is.

You make a very good point Rick. It is true I have become frustrated with the almost constant repairs I have been making to the K since I purchased it 5 months ago.....and the words THIS IS A BMW IT'S SUPPOSED TO BE RELIABLE have passed my lips on ocassion. However, I have also done 8k miles on it as I have a long commute (and an old K is all that budget would allow) and this is well and above average millage.

Perhaps I should be a bit more realistic about a 20+ year old bike and except that if i cointinue to do such distances then time in the garage, fixing, replacing, repairing, gluing, welding and dare I say bodging is envitable. Perhaps I should just take solace in how much I am learning.

Anyway enough of this chit chat and sole searching......back to the garage for some Zen.

Thanks for the resposes guys. Must admit I bought the K for a few reasons: 1 Lack of dosh, and 2 their reliability record. I know it's old, but had only done 40 odd thousand miles when I got it, so (in my naiveté) assumed it was good for another 40K, so long as I looked after it (which I have, oils, brakes etc, not thrashing it around). I never expected it to be perfect, but am a little dissappointed that the things that are going wrong, are the most expensive things and most difficult to sort out on my own.

I've had another look at it this morning, and decided to at least have a go at the clutch, whilst trying to blag a newer alternative from the shop where I bought it (sold as seen). The main problem is getting the people I have been working with to believe the bike won't break again in the middle of an important job. Pity really, I enjoyed flying the flag for good ol 1980's german engineering.

Speak t'yall later.

Terry.

Terry surely the cable let go because the pivot pin in the clutch arm at the rear of the bike is abit ceazed. just take it apart and grease it and buy another cable. the clutch and box should work again as before once you ease the selectors through thier circuits a few times without you having the whole bike on top of them. you know as well as we do a multi faceted business like currier work requires your utmost dilligence when it comes to your tackle of choice. (Oh i wish this had a spell checker) glad I'm not a typist! you will do well with it if you persevere

K75cster. Thanks for that Mr, you have given me a glimmer of hope. I'm hoping to start taking it to bits again later today, will let you know what I find. Thanks again for the encouragement. Terry

Good news......K back together and everything is working as it should. Thanks for all the help and advice. Unfortunately it is all coming off again within a month to do the clutch splines, but at least it's clean, sheared bolts replaced and liberally coated in copper slip so should be less traumatic.

Good one Giles aced it, Terry we will be listening for the shed mutterings, hope it all comes together

Good news Giles. I've got to do mine too in about a month but without the benefit of copper grease!
88KE