Gearbox.

[Cornish Bob]

Hi,
my gs1150 gearbox suffered a bearing failure on the front of the layshaft at 35000m. On stripping the box I also found that mainshaft splines and those on the clutch friction plate where badly worn so I replaced the shaft and all the bearings.
4000mls later another bearing shot, this time on the rear of the layshaft.
The bearings came from BSL after I took one in for them to see.
3 questions, 1, could they have supplied the right size but wrong tolerance bearings? 2, can anyone come up with the right spec. ones? (Not just a BMW part no.). 3,Why do BMW fit bearings with seals inside a gearbox which has oil ways machined in the caseings, when all the seals would keep out would be oil....?
Cheers,
Bob.

 

[stephenm]

3) Why do BMW fit bearings with seals inside a gearbox which has oil ways machined in the caseings, when all the seals would keep out would be oil....?
Cheers,
Bob.
>>
I believe the seals are there to keep the suspended metal particles in the gearbox oil out of the bearings. The 1200GS is set up this way.

Stephen

 

[Cornish Bob]

Cheers,
I have also found out the problem with the bearings, they are a common size which is what I was given from BSL but they should have a greater tolerance (c3) to allow for expansion due to higher load etc.
Rob.

 

[(RIP) Bin Ridin]

I read these bearings described as ultraclean bearings - they do not run in the gearbox oil. this was an early mod to the first RS gearboxes which clapped out in the mid-nineties.