Driveshaft splines

[Andy VH]

My 94 R1100RS has 115,000 miles on it. I have put all but 3,000 of those miles on it myself. I try to do all my own work, even to the point of clutch jobs and pesky leaking rear main seals.

Since my 94 is an early spec model it had some of the typical tranny problems. I had the tranny out at 50k for a failed throwout rod bearing. BMW covered 80% parts and labor, and I did the tranny removal and installation.

At 68K an internal bearing failed as confirmed by my dealer. Again, I plulled the tranny myself, and with great help from my dealer (Mischler's of Beaver Dam, WI) I got a brand new 96-spec tranny in a box, which I installed myself. Also installed a new clutch friction disc at this time, using the old pressure plates.

Then at about 110K I was due for another clutch friction plate (cause I used the old taper worn pressure plates at my last clutch work, KNOCK ON HEAD!!). So I again pulled the tranny and installed a whole new clutch assembly. Trust me, when its clutch repair time, go with the ENTIRE package as BMW recommends. Don't be a CAB (Cheap A$$ Biker) like I typically am.

So, each time I pulled the tranny I had the driveshaft in my hands. I lubed the splines with BMW Molycoat and was always careful about driveshaft joint phasing. Anyone (Paul Glaves maybe?) have any input as to what I can expect for driveshaft life? I do notice a humming sound when the bike is leaned over in turns that I don't notice when totally upright going straight. Not sure if that's related to wheel bearings or drveshaft/pinion/ring gear wear. Any comments?

[chrisZ]

Andy,

The humming you hear are very likely the tires. I have the same humming on my RT and a bit less on my Honda VFR. The difference in humming on my bikes is likely due to different tires used. As far a the splines are concerned, I heard that the BMW lube dries out and goes white powdery within 20K miles or so. Some have recommended using Honda Lube for this application.

Good luck.

[AntonLargiader]

...have any input as to what I can expect for driveshaft life?
Most of them never wear out. I haven't seen bad splines on any Oilhead driveshaft. I had a U-joint go bad on my '94 RS but that's a rare failure.

[brianfisk]

I had a driveshaft universal go on my 97RT at 165000 miles. Just one joint eveything else was in great shape. No dried out lube at this time. The shaft was out at 115000 when I had cluch put in. So I don't know if it was lube or not.
I not complaimg just because one joint failed, but, you have to replce the entire shaft. plus I did swing arm parlever bearings at the same time. It was all my labnor but still cost around $500.


Brian Fisk

[Andy VH]

Thanks for the replies. I think my splines are in good shape from what I have seen each time I had the back of the bike apart. From what I have read of BMW driveshaft spline problems in the past they are either related to a problem that BMW took care of early on, or problems related to poor maintenance of some sort.

I'll check mine about once a year when I do my tire changes, from now until I do see a real problem wear wise.

[PGlaves]

Little late to this party, but ....

The splines on the Oilhead driveshafts just are not an issue like on the monolever K bikes. I attribute this to the fact that the splined section is longer spreading the load over a larger area. There may be a metalurgy difference too.

My experience with these driveshafts is that anywhere between 150,000 and 200,000 miles the universal joints are likely to be worn. Voni had one go - disintegrate - somewhere between 185 and 202K - I forget which. On her other R1100RS I detected some looseness and clicking in the rear joint at about 170,000 miles. There was no significant sign of spline wear on these shafts. I'm with Anton - the only failures I've seen are U joints, not spline wear.

To a degree the life depends on the bike's typical weight loading because this determines the angles at which the universal joints typically run. More heavily loaded bikes have straighter driveline deflection angles so more weight might be good. In really hilly country the driveline load from the weight might be an issue but usually it is drag (wind resistance) that puts the most load on the driveline while tooling along down the road.