R1200GS Rear Drive Breather?

[(RIP) Bin Ridin]

Hi,
Anyone know where / how the 12gs rear drive gearbox breather is / works?
Bin

 

[Chris Terry]

Do you mean the "Final Drive" (the bit the back wheel bolts too)? If so it has no breather that I know of. It's a sealed unit that is less than half full of oil and only gets warm, so doesn’t need to breathe.

 

[(RIP) Bin Ridin]

Yep, that's what I thought, but I must say it seems very odd.
My right side seal showed a wee smear of oil after a very long hot day, nothing since. Seemed like it was an overpressure problem.
I wonder will it be like the "sealed for life" business, where in some future model, a breather will be added...

 

[Daffy]

The seal on the ABS sensor is not very tight, my guess is that any overpressure will leak here before it gets high enough to make the seal weep.

Don't know about non abs versions tho, perhaps they have a blank in place of the sensor with a similar seal arrangement, anyone seen the non ABS

 

[Chris Terry]

Yep, that's what I thought, but I must say it seems very odd.
My right side seal showed a wee smear of oil after a very long hot day, nothing since. Seemed like it was an overpressure problem.
I wonder will it be like the "sealed for life" business, where in some future model, a breather will be added...

Are you sure that there is oil in the FD?. Have you changed the oil?? to be sure I would do both to be on the safe side. If it's under warrantee I would insist that BMW check the oil as it's been leaking , the only way to do that is to drain and refill with the correct quantity of oil.

 

[(RIP) Bin Ridin]

I have changed the oil a few times, so that's not the worry. I am very curious as to why the thing has no breahter, maybe the designer wants it to stay real clean, and not allow water in if submerged, but the pressure increase problem puzzles me.

Ah well, if that's all I have to worry about....

 

[Spout]

The seal on the ABS sensor is not very tight, my guess is that any overpressure will leak here before it gets high enough to make the seal weep.

Don't know about non abs versions tho, perhaps they have a blank in place of the sensor with a similar seal arrangement, anyone seen the non ABS

If you're talking about the sensor in the final drive - it's the speedo pick up. So non abs have them aswell.

 

[Chris Terry]

IMHO I can't see there is a "pressure problem", it's not full of oil, the temperature between hot and cold is not that great. Even if there is a slight increase in pressure when hot the oil seal should cope.
I reckon oil leaks are down to shaft movement and or seal wear