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Drive shaft Maintenance? '80 R100T

Posted: Fri May 27, 2022 5:43 am
by kmisterk
I've put just over 2800 miles on the bike since I've owned it. The odometer, being 5-digit only, shows ~64,000 miles.

I'm fairly certain the previous owner was an avid maintenance stickler, ensuring it got its assorted services at various mileages. I want to know what I should be looking out for, assuming it's got 64,000 miles or so (I don't believe it has turned over), regarding the Drive Shaft.

What kind of maintenance does the drive shaft actually need, if any? I know these types of setups typically are praised for their low-touch maintenance schedules, but when would be a good idea to check on it, and what, exactly, needs checking?

Re: Drive shaft Maintenance? '80 R100T

Posted: Fri May 27, 2022 11:12 am
by gspd
Your shaft runs in a bit of oil and is virtually maintenance free.
Check the u-joint for excessive play every blue moon.

The later double-jointed Paralever driveshafts run in a dry swingarm and tend to be less durable.

Re: Drive shaft Maintenance? '80 R100T

Posted: Fri May 27, 2022 12:22 pm
by kmisterk
gspd wrote: Fri May 27, 2022 11:12 am Your shaft runs in a bit of oil and is virtually maintenance free.
Check the u-joint for excessive play every blue moon.

The later double-jointed Paralever driveshafts run in a dry swingarm and tend to be less durable.
My brother mentioned a buddy of his with a shaft drive bike seizing on him, the shaft locking in place. I don’t think he was referencing a BMW like this, just a generic shaft-driven bike.

Is this something that I should worry about on this bike? Do I need to do anything with the oil at any given mileage intervals?

Re: Drive shaft Maintenance? '80 R100T

Posted: Fri May 27, 2022 4:14 pm
by Rob Frankham
As GSPD says they're pretty bulletproof. I have suffered a broken spring in the damper but that's something you won't find till it goes.

The only bit that might give trouble after a very long life is the hooke joint (UJ). Whenever you get to see it, it's worth flexing it by hand to see if it's getting loose or notchy. The movement in both planes should be smooth and there should be no detectable axial movement in either direction... needless to say there shouldn't be any radila movement either. The joint can be replaced without replacing the whole shaft but it's best done by a specialist shop...

Rob

Re: Drive shaft Maintenance? '80 R100T

Posted: Wed Jun 08, 2022 7:43 pm
by ME 109
Hello all,
the cush drive/shock absorber shafts like on my '81 can suffer a broken spring, although it's rare.
The spring loaded coupling components can wear to the point of making less smooth throttle roll on. A step/abrupt angle change forms on the contact faces of the two parts. More of a clunk than progressive smooth torque take up.
Subject to how the bike is ridden, the same drive shaft with another rider might never fail.

I recently replaced the two couplings and spring, and uni joint. About 300,000 k's on the couplings, but they had needed attention for a while. I did the fd spline and wheel cup spline as well, to reduce drive train back lash as much as possible.
The repairs made a significant improvement in the on/off throttle transition, much smoother.
Just the gearbox worn cush drive to address, although I rebuilt a spare gearbox that Timo from Hawaii gave me, It has very good input shaft components so I'll swap it in.