2011 R1200GS - Drive line sliding motion??

G'day,

I read somewhere that on the newer bikes like mine, there is no sliding motion in the drive line, and that therefore, because there is no sliding motion, there is no need to drop the rear drive periodically to lube the splines where the drive shaft goes into the final drive. Am I correct in that understanding? Certainly, I don't see drive shaft spline lubing mentioned as a maintenance item in the 6th edition BMW repair DVD that I have for my bike. And I've never seen it mentioned on any work orders from the two dealers who have worked on my bike since it was new (the bike has 46,000 km on it and it is still under warranty).

I know these splines were lubed as part of the re-assembly procedure on the earlier models, because the rear drive had to be dropped to drain the rear drive oil. But since my bike doesn't require the final drive to be dropped in order to change the oil in the rear wheel final drive, is it specified\necessary to drop it anyway, just to lube the splines??

A related question...has BMW issued have some Service Bulletin or something that calls for periodic drive shaft spline lubing, that they didn't bother mentioning in their repair DVD? (After a while, I am starting to get nervous that the BMW repair DVD isn't all inclusive, and can't be relied upon by do-it-yourselfers, to be aware of all the maintenance requirements).

Thanks for any insights.



Dave McDougall
2011 R1200GS

There is minimal sliding motion. The oilheads had a two piece drive shaft that changed length with suspension movement. The two pieces are splined. The hexheads use a one piece drive shaft. The design is such that the swing arm pivots are at the same location as the U-joints. The front of the drive shaft is attached to the transmission output with a spring clip... there is no sliding. The rear of the drive shaft is attached to the FD input. There may be some sliding at that junction. More important, IMHO, is that the rear protective boot can come loose and or otherwise let moisture get at that junction. Periodic cleaning and application of grease is a good thing.

I pulled the drive shaft of my GS at 60,000 miles because I was changing FD fluid at the time and on the GS pulling the DS is easy. There was no wear to speak of on transmission output splines or FD input splines. The main reason for pulling the DS was to check the front U-joints. They were OK, too. Putting the DS back is easy once you realize there is no room for fingers AND eyes so you have to do the job by feel.

The clutch still moves on the transmission input splines.

[img]http://snafu.smugmug.com/Motorcycles/R1200GS/p-20110125-1138-2676/1171479763_BDDyA-O.jpg[/img]

+1 on Marchyman's recommendations.

I'd suggest a 24k mile interval would be good for the driveshaft, and once the front is lubed with a decent lube (Wurth 3000 comes to mind, there are other suitable greases), I'd forget about it since it is clipped in place and doesn't slide at all. The rear may have a tiny bit of sliding movement, but nothing like the older driveshafts did (especially the monolever ones).. so 24k to check/clean/lube it should be adequate. If you find it's still fine at 24k miles, you may want to extend the interval.

Most important is make sure the rubber boots are intact and installed correctly (with the internal plastic expanding clip in place, unbroken).. these are the primary defense for your splines and U joints.

ntxt

Sliding is not the only determining factor for spline wear. For example on a truck with a PTO (Power Take Off) mounted on a transmission with a hydraulic pump bolted solid will have spline wear. There is no sliding motion at all but the splines can and do wear out. In this case you will have a male and female spline made of the same hardness material and the two will just work against each other and fret. The splines will have similar loss of material. Lubing definitely will slow or eliminate the loss of material. Once material is lost now there is room for the two objects to have movement and start bouncing if you will against each other with the power pulses of the motor.

Happy Riding