This Is The EPIC Soggs 92K75 MAGA Thread

[Chaos]

Many vehicles have splined shafts that are not prone to failure.  BMW dropped the ball on this IMHO, a shame since the rest of the drivetrain seems to live forever.

[Laitch]

You think I’ll get many miles from what you can see?

If many miles means 3000–5000, that is doubtful. Not goosing the moto through its gears nor puttering along in a gear too low might extend the mileage but when the tips of those sawtooth-looking splines on the driveshaft break off, you won't be going anywhere. That happens suddenly. The final drive splines are worn, but are not in dire condition like the driveshaft. Ideally both would be replaced at the same time.

What year was the moto manufactured? The splines were hardened in the late '80s according to one history at at Anton Largiader's website. Lack of proper lubrication, as Chaos has indicated, certainly contributes to their wear.

[The Mighty Gryphon]

Many vehicles have splined shafts that are not prone to failure.  BMW dropped the ball on this IMHO, a shame since the rest of the drivetrain seems to live forever.

The linear motion is only an issue on drive shafts with a single u-joint.  Two properly phased u-joints will cancel out that motion, and CV joints inherently have no relative motion between the input and output. 

I suspect that someone at BMW said "hey, the motion is so slight it's nothing to worry about".  Especially, since adding another u-joint to the Monolever would add a lot of cost and unsprung weight to the rear wheel.  Finally, they couldn't hold off any longer and the Paralever was born.

[Soggz]

If many miles means 3000–5000, that is doubtful. Not goosing the moto through its gears nor puttering along in a gear too low might extend the mileage but when the tips of those sawtooth-looking splines on the driveshaft break off, you won't be going anywhere. That happens suddenly. The final drive splines are worn, but are not in dire condition like the driveshaft. Ideally both would be replaced at the same time.

What year was the moto manufactured? The splines were hardened in the late '80s according to one history at at Anton Largiader's website. Lack of proper lubrication, as Chaos has indicated, certainly contributes to their wear.

*Gulp*....The bike is 1988. To be fair,I did buy this bike as a project, but I didn’t intend to spend much more on it...however, looking at the state of the shaft, looks like I will have more time to save up for the parts, if If I can find any!
What an awful blow!
Still, I still have the trusty CX500.(that took me 2 years to get on the road. Still needs new rings).

[Soggz]

This

[Chaos]

All is not lost, with gentle riding and a generous lubing those splines may last a while, just be aware you may get stranded at any moment and plan accordingly.  That is one of the joys of my Russian bike, it has actually been fairly dependable but the thrill of never knowing when a catastrophic mechanical or electrical breakdown will occur keeps the adrenaline flowing.

[Soggz]

All is not lost, with gentle riding and a generous lubing those splines may last a while, just be aware you may get stranded at any moment and plan accordingly.  That is one of the joys of my Russian bike, it has actually been fairly dependable but the thrill of never knowing when a catastrophic mechanical or electrical breakdown will occur keeps the adrenaline flowing.

Ha Ha, I admire your way of thinking! Yes, the thought of breaking down will keep me on my toes, I am a member of our local automobile association,(AA),so at least I can get trailered home!
I would probably only do about 2000 miles in a year, on it.

[szabgab]

Hi. Got the rear drive off.
Do these look ok?
A8603DB1-7C59-4623-B3B3-14494D99C66A.jpeg (42.6 kB . 768x576 - viewed 513 times)

Hey,  the final drive is pretty much shot I am afraid :(

Edit -  For some reason I have not seen,  I am very late to this party :)  Nevermind,  keep your eyes pealed on the bay or talk to the UK bmw place,  they do spline replacing

[Soggz]

Hmmm... Bugger!
Yes, I will have to start looking for spares. I will put it all back together, though, to see how long it lasts. My injectors should be back in the next couple of days. At least I can see how the engine runs.

[Laitch]

Hey,  the final drive is pretty much shot I am afraid :(

Edit -  For some reason I have not seen,  I am very late to this party :) 

That's not the final drive you've copied into your post either. 

[Soggz]

Final drive?

[Soggz]

Drive shaft

[Soggz]

I wonder if liquid metal would take up the gaps for a while?

[szabgab]

That's not the final drive you've copied into your post either. 

Sorry Laitch, you are right obviously, I meant the driveshaft, it is just my full-on man flu, that makes my already questionable brain activities completely foggy :)

Soggz - You can have a look at the bay, as I said, but for some reason or other the 16T versions are VERY scarce. I was in your situation probably two-three months ago and it is a shock, when you realise, you do have to cough up for one of the most expensive parts :(

Anyway, being in the UK is your luck, as www.motobins.co.uk is selling replacement spline ends for around 65GBP and they also do a spline repair for UK RESIDENTS ONLY for around 100GBP. Have a look at their website as that will get you basically a 'new' driveshaft (the other end does not wear as much and if the U joint is fine, you should be fine for a good few thousand miles)

[Soggz]

Thanks. For some reason, I can’t get onto the site. I will try again later.

[Laitch]

I wonder if liquid metal would take up the gaps for a while?

Want to be a true pioneer? Try some of this stuff and let us know how it all turns out.

[szabgab]

Want to be a true pioneer? Try some of this stuff and let us know how it all turns out.

Although this sounds like snake oil I would be very interested to see, if it works. I wonder, how it is possible separate the socket from the shaft, if you have filled the gap with gluey material. Obviously very little spline material is left on the driveshaft, but if you can get it aligned correctly, and separate the parts afterwards, you would end up with a very precisely fitting pair of FD-DS. Also probably the new plastic-metal would break off in chunks after a short while damaging everything in it's path, mainly the final drive input seal, mating surfaces and so on

[Laitch]

Soggz - You can have a look at the bay, as I said, but for some reason or other the 16T versions are VERY scarce.

His driveshaft and final drive shaft are 20 tooth. The reason secondhand 16T versions are very scarce is that they were only used from 1983 to February of 1986.

[Soggz]

His driveshaft and final drive shaft are 20 tooth. The reason secondhand 16T versions are very scarce is that they were only used from 1983 to February of 1986.

Ah! 20 tooth.
Good, this explains why the 16T is over twice the price of the ones I have recently seen. That’s something, at least!
Thanks for that, I e stop sweating so much now! Lol

[szabgab]

Ah! 20 tooth.
Good, this explains why the 16T is over twice the price of the ones I have recently seen. That’s something, at least!
Thanks for that, I e stop sweating so much now! Lol

Aaah, I'll just shut up for tonight. My brain is obviously in reverse mode, sorry for that Soggz. Laitch is, again, absolutely right. BTW I had it all mixed up in my head, the 16t versions are not so rare after all, as they are the ones, you'll find, if you search for K100 driveshaft on ebay.... If nothing else, at least the motobins replacement shaft ends are the correct, 20T versions :) Also not to feel so much down, look at my splines, as they were not too long time ago - http://www.motobrick.com/index.php/topic,11767.msg102910.html#msg102910  For me this turned out to be a costly repair, as apart from the price of the shaft, my post office charged me a staggering amount on top as import duty, handling fee and all that crap, but apparently you do not have to pay anything lextra in the UK for second hand goods

[Laitch]

Aaah, I'll just shut up for tonight. My brain is obviously in reverse mode, sorry for that Soggz. Laitch is, again, absolutely right. BTW I had it all mixed up in my head, the 16t versions are not so rare after all, as they are the ones, you'll find, if you search for K100 driveshaft on ebay.... If nothing else, at least the motobins replacement shaft ends are the correct, 20T versions :) Also not to feel so much down, look at my splines, as they were not too long time ago - http://www.motobrick.com/index.php/topic,11767.msg102910.html#msg102910  For me this turned out to be a costly repair, as apart from the price of the shaft, my post office charged me a staggering amount on top as import duty, handling fee and all that crap, but apparently you do not have to pay anything lextra in the UK for second hand goods

You didn't shut up. :giggles

[Soggz]

Aaah, I'll just shut up for tonight. My brain is obviously in reverse mode, sorry for that Soggz. Laitch is, again, absolutely right. BTW I had it all mixed up in my head, the 16t versions are not so rare after all, as they are the ones, you'll find, if you search for K100 driveshaft on ebay.... If nothing else, at least the motobins replacement shaft ends are the correct, 20T versions :) Also not to feel so much down, look at my splines, as they were not too long time ago - http://www.motobrick.com/index.php/topic,11767.msg102910.html#msg102910  For me this turned out to be a costly repair, as apart from the price of the shaft, my post office charged me a staggering amount on top as import duty, handling fee and all that crap, but apparently you do not have to pay anything lextra in the UK for second hand goods

yours look better than mine,don't they? How long did you carry on using it before you replaced them?

[szabgab]

yours look better than mine,don't they? How long did you carry on using it before you replaced them?

I am not sure if it does, both of the shafts are pretty much shot. Laitch recommended to replace mine immediately so I used it for an another 2-300 miles before I received the other shaft. Who knows, how long it would have lasted though the PO did not even know, the shaft needs maintenance so he was lucky and I bought a time bomb

[Soggz]

Like me then!What with the new fan and the injection clean, tank interiors, etc, I’ve gotton too far into it, to back down!
Still, plenty of time.
I’ll have to save up for another shaft and rear drive.

[szabgab]

Like me then!What with the new fan and the injection clean, tank interiors, etc, I’ve gotton too far into it, to back down!
Still, plenty of time.
I’ll have to save up for another shaft and rear drive.

Yep, just like you. I had also some alternator issues, some electronic glitches, cracked big elbow on the manifold, broken air collector box, crappy brakes and other bits and bobs I do not remember anymore. If I look back, since I have owned this bike, I have spent more time underneath it in oily overalls, than sitting on it but it is starting to shape now.

Someone else might chime in on this, but in my opinion you should probably worry about the driveshaft first as the final drive splines look to me in somewhat better shape. If you are like myself - riding the bike for 2-3-4000 miles a year and will probably sell the bike in the next five or so years you are - again in my opinion - not putting in enough miles to chew up a new driveshaft with the worn final drive shaft. Just make sure, you lube the hell out of that joint and do it regularly, even every year or so and you should be good...