Twin Cam final drive failure question

[MIKE R]

I know that a lot of GS riders have had final drive failures.......I've had 3, but all on my 1150!!!!!

I check this site fairly regularly but cannot recall any win cam owner reporting a final drive failure!

Am I having a senior moment or have BMW finally solved the problem?

So has any owner of the twin cam had a final drive failure?

Mike

 

[patzx12]

I did not hear of any failures yet.

 

[(RIP) Bin Ridin]

Mine went at 18,000kms.
Vibes in footrests, high speed rumble when spinning wheel by hand on main stand.
Input shaft bearings gone. Major crap in the oil when dealer checked it.
New unit fitted by dealer (took one off a new bike in stock).
I got the drive oil changed at the 1000km service, but cannot see connection with the bearing failure assuming he put enough oil in. If he did not, hard to see how it would last that long. If wrong oil, maybe would cause.
I changed the drive oil in the new bevel box at +2,000kms and recently at +10,000kms and it is perfect.
Observed that the driveshaft spline coupling is a neat fit onto the pinion shaft, free enough and clean but neater than the one on my last bike. Possibly forcing the shaft in and out with suspension movement but unlikely.

 

[wheelnut]

Mine went a fortnight ago at 17k - loss of drive exiting a roundabout with lots of expensive sounding noises

 

[JohnnyBoxer]

Mine went at 18,000kms.
Vibes in footrests, high speed rumble when spinning wheel by hand on main stand.
Input shaft bearings gone. Major crap in the oil when dealer checked it.
New unit fitted by dealer (took one off a new bike in stock).
I got the drive oil changed at the 1000km service, but cannot see connection with the bearing failure assuming he put enough oil in. If he did not, hard to see how it would last that long. If wrong oil, maybe would cause.
I changed the drive oil in the new bevel box at +2,000kms and recently at +10,000kms and it is perfect.
Observed that the driveshaft spline coupling is a neat fit onto the pinion shaft, free enough and clean but neater than the one on my last bike. Possibly forcing the shaft in and out with suspension movement but unlikely.

Correct shimming at the factory is the key
Get it right & it'll be fine
Get it wrong & it'll break prematurely
All down to who & how well they shim it up, during build - I'm led to understand

 

[MIKE R]

Correct shimming at the factory is the key
Get it right & it'll be fine
Get it wrong & it'll break prematurely
All down to who & how well they shim it up, during build - I'm led to understand

You could be right.

On the 1150 the first 2 replacement drives were repaired by a local independent.

When it went for the 3rd time, I had the unit shipped down to Scriminger Engineering.

Hope all is well for many miles now.

Mike

 

[jwpzx9r]

I am somewhat confused by the statement "final drive failure". In as much as is this the final drive or the wheel bearing? I say this because in my book a bearing running is not a failure of the final drive its a bearing and wheel bearings go regularly. I have had it happen on a number of occassions with previous bikes and cars. So is it the final drive or the wheel bearings. I know that the GS is slightly different because its a shaft drive but the bearings supporting the drive are not the final drive as such... and in my book a statement saying my final drive is shagged is more dramatic and costly sounding than saying I've run a wheel bearing, which is an easy if messy fix!

 

[Sgt Bilco]

I am somewhat confused by the statement "final drive failure". In as much as is this the final drive or the wheel bearing? I say this because in my book a bearing running is not a failure of the final drive its a bearing and wheel bearings go regularly. I have had it happen on a number of occassions with previous bikes and cars. So is it the final drive or the wheel bearings. I know that the GS is slightly different because its a shaft drive but the bearings supporting the drive are not the final drive as such... and in my book a statement saying my final drive is shagged is more dramatic and costly sounding than saying I've run a wheel bearing, which is an easy if messy fix!

Good point and I think you are spot on. The problem arises on the 1200 because it's easier to replace the whole final drive unit when the bearing fails. On the 1150, it's an hour or so's job to change the bearings on the original drive.

 

[jwpzx9r]

Good point and I think you are spot on. The problem arises on the 1200 because it's easier to replace the whole final drive unit when the bearing fails. On the 1150, it's an hour or so's job to change the bearings on the original drive.

Hi "Sarg" While I am not disagreeing that it is probably easier just to replace the whole FD unit, the very detailed post by Pat et.al. suggests that it is an easy fix once the drive has been drained and removed. The only really difficult bearing appears to be the pinion bearing which needs special tools and also mechanical coupling to an imovable bench to remove. Other than that it looks doable to me and I'm no engineer!... shimming apart, but I think that Pat said he thought that shimming was not absolutely required for the job to be a good un.