ring and pinion 1986 r80

[bighairbrian]

is the final drive something which can just "go" one day?

Here's my story.

Hi, name is brian, in 2007 i bought a 1986 R80 with about 85xxx miles on it. The Previous owner bought it basically new and took excellent mechanical care of it.

I rode it in 2008, then parked it doing appropriate winterizing things. it sat until this spring.

So, early MArch all the fuids are changed, and

Finally got insurance on it, started riding to gas station, after about 1 kilometer the rear of the bike started knocking-making grinding noises. I limped it home.

from everything i have read it seems this could be a ring and pinion issues. But is this something which just goes? there was no evidence of it going from my previous riding (although that was a few years ago now).

When on the centre stand the rear wheel will spin there is an obvious point in the rotation where the noise occurs - consistently.

is this something which will just happen or would it be more gradual?

Any ideas what else it could be? I am not in a place where tools or work space is an option so i am trying to get an idea of what it could be before sending out to mechanic.

thanks

[chasbmw]

I don't really know monos very well, worth checking that the 4 bolts holding the drive shaft onto the output of the gearbox are all in place. If one of them backs out, it can cause the symptoms you report.

Otherwise likely to be one of the bearings in the final drive, rather than the ring and pinion, but draining the oil should give you a lead.

[barndeadr80]

Have you backed off on the rear brake adjuster to see if it makes any difference? Pulled the wheel and looked at the brake parts and the "drum" which is part of the wheel? Also, when you spin the wheel, the driveshaft is turning too.

[bighairbrian]

i will back off the brakes today and see where i am at - Chas -i did check the 4 bolts and they are secure - curious about the bears as when we changed the oil nothing suspicious appeard.

thanks for the input.

brian
BC
Canada

[chasbmw]

You won't see debris in the final drive oil if the bearings have gone, check the wheel for wobble.