R100GS Drive shaft failure

[Voyager]

Right . . Some pics of old and new silencers.

The old one is above the new one. As can be seen, the upper mountings are not identical - welded on the old one, bolted on the new one.

This is clearer in this pic. As you can see, the bolted brackets do not follow the same line as the old ones, meaning that the larger (front) bracket has to be on the inside of the frame and spaced out to follow the alignment of the other two (plus the pipe connection). The top seam on the silencer prevents the bracket being reversed.

The lower bracket that shares a sub-frame bolt is the same on both.

Finally, a view along the top of both silencers shows the different alignment. I thought about reversing the rearmost bracket but as it isn't symetrical the rear frame mounting bobbin won't line up.

I think the trick is to get the lower and rear brackets attached and then work on the centre one. I didn't do this properly the first time and split the rear rubber mounting.

I may fabricate some new brackets if my next attempt doesn't work, but they won't be in stainless unfortunately.

Now to get on with re-plubming the downstairs toilet/shower room before SWMBO comes home and finds me on this site again ).

Bob.

 

[fritz]

Two quickies

Shafts - don't rule out replacement with new. The one I put in has lasted no worries including some serious use. Search way back and you'll see how knackered the one was that it replaced. Bikes on 100,000+ miles now - maybe the newere shafts are improved (looks same)

Exhausts - the use of the grey heat paste stuff (forget name - Optimal?) is highly recommended. Taking off and back on is POP using this stuff.

(incorrect alignment can lead blowing head gasket and eventual burning away of exhaust port....you'd have to leave it for months or 12,000 miles for that to happen though really must repair They really do take some hammer )

 

[Mike Wilkins]

Exhaust not shaft I hope !!

Thanks all for the helpful info.
I want to tick off the exhaust mounts before I attack the shaft (hopefully not neccessary) - have ordered various parts from Motobins and will have a go at the weekend. If this works I'll just have to bodge the gaiters with strips of moutain bike innertube over the perished bits for the mo and problem sorted.
If its the shaft then I know what to do to change it - just need to buy a few tools and when its done sorted for a long time.
Bob - thats my baby - much the same apart from no panniers and bad boy pipe !!
Thanks
Mike

 

[Graham W]

Graham W

Mike,
Have you tried simply rotating the rear wheel with the bike on the stand and the gearbox in neutral? It should rotate in both directions pretty much perfectly smoothly - if you get any clicks, tight spots, graunches etc when rotating it in either direction it would tend to point to the shaft being suspect. There shouldn't be any play at all in either of the joints. Sorry to be pessimistic but the symptoms you describe are exactly what mine did when the shaft failed - having had one go it's not pleasant, and is potentially damaging to other things so for the sake of a relatively easy job I'd be inclined to pull the driveshaft to check it if in any doubt. It doesn't take long and even if it's fine then the splines and pivot bearings will appreciate being greased.

I hope for your sake that it is the exhaust, although having fiddled with the mounts and alignment on mine, and ridden miles with a split rubber bobbin it doesn't seem to have made the slightest difference, and certainly nothing that could be decribed as heavy vibration.

Good luck

 

[(RIP) pastyman]

Seems to me that the drive shaft is the one biggest problem with the paralever gs's so surely there must be some enterprising engineer out there who could make a better job of it than BMW. If the yanks can provided what seems an excellent and comprehensive service, including three options of replacement rubber shock thingy, and similarly the bloke in germany, then why is there no one here able to do the same? After all probably some little Turkish immigrant in germany put the thing together in the first place so a qualified engineer her should be able to modify it to be able to fit standard replacement uj's.

If such a service was available how many paralever owners would take the opportunity and so make it viable?

Or am I being thick and showing my limited knowledge of whats involved.

 

[Graham W]

Or am I being thick and showing my limited knowledge of whats involved.

Dunno about that, maybe I am too. When I looked into it I heard of people who had had the joints replaced in the UK, and then had them fail again 15K or so later. Eric Demant reckons his will go 50K miles and then the joints can easily be replaced - I think he beefs the yokes up to take a heavier duty joint instead of just doing a 'like for like' replacement, anyone know for sure? I went for a new shaft for quickness but if it lasts as short a time as the last one I'll need another in a couple of years again You'd think it would be in the interest of Motorworks / Bins / Sherlocks to commission someone to do the same thing in the UK - they must sell shafts fairly regularly.

 

[Redboots]

I think he beefs the yokes up to take a heavier duty joint instead of just doing a 'like for like' replacement, anyone know for sure?

He welds a ring onto the yolk to take the cir-clips. The UJ is not the standard item but one that he sources... has slightly larger needle rollers.

If you want a "proper" job, he sells a solid shaft, but thats €500 or so. He says you should use it if you like to off-road a lot

To pic is standard. second one is Erich's mods with nipple
http://www.ukgser.com/forums/attachment.php?attachmentid=84838&stc=1&d=1203608158
shaft1.jpg
http://www.ukgser.com/forums/attachment.php?attachmentid=84839&stc=1&d=1203608171
shaftn1.jpg

John

 

[(RIP) pastyman]

Glad some of you agree. The ones above look similar to the one from America
and he can do the shock as well, Point I am making is that surely we as BM owners can persuade someone to do these in this Country. seems as if its an engineering problem and not magic.

 

[Paul Rochdale]

http://www.advrider.com/forums/showthread.php?t=130764&highlight=Hendersen

I agree. It does seem to be a relatively simple solution to this problem although quite why it's so expensive is a mystery. I guess that the yokes of the UJ need to be machined out to fit a bigger one and one with a grease nipple? Then the circlip 'rings' need welding on. The Hendersen propshaft replaces the rubber with a type of plastic.

 

[Redboots]

With the mod'ed shaft from Erich, you also need to ream out the swinging arm casting to get the shaft through it, at the gearbox end.
The shaft has grease nipples on both ends. The bevel drive ind is plugged and a nipple supplied to screw in when needed.
The rubber is not replaced though he will tell you if its cattle trucked.

J

 

[(RIP) pastyman]

So, as I said earlier, there is an engineering solution but not in this Country!!
Im surprised the likes of Motorworks have not done it but maybe no one has asked them. or perhaps if interested members touted engineering works in their areas we may get a result.. even if it is relatively expensive to have the mod done, subsequent renewal should be cheap and not too difficult. would be a pain if in a few years our paras were on the scrap heap because the drive shafts were "unavailable" Make the mono lot larff.

 

[Rob Farmer]

Make the mono lot larff.

Happens everytime I read a Paralever driveshaft thread

To quote Scriminger's on the Mono G/s:-

"The drive shafts are indestructible, unlike the later Paralever systems"

"The 800cc twin engine is the best they ever made"

 

[Mike Wilkins]

What a tosser fearing the worst !!

Thanks for the help guys - it was a badly fitted exhaust.
I re-fitted it and included some missing parts (rubber mount and alloy gasket between y piece and pipe) and spaced everything so that nothing was under tension - problem solved.
So - what have I learned - I still need to change the gaiters and probably the output shaft seal (breather hole in bolt not blocked)
- I now know how to do the shaft if and when
- I now have the tools (12mm key and 27mm box) if anyone in my neck of the woods needs to borrow them
Cheers
Mike

 

[Rob Farmer]

Good news Mike. I'm glad it was nothing major

 

[Voyager]

Thanks for the help guys - it was a badly fitted exhaust.
Mike

Result


Bob.

 

[(RIP) pastyman]

Go have a lie down........ You must be exhausted!!!!

 

[Ogmios]

Happy Endings - i love 'em.