BMW final drive boot replacement

[KrisZ]

It’s an easy job, but the boot is quite pricey. I paid around $70 from an eBay vendor, but they go for over a $100 from other online stores.

Mine was cracker, I presume from the old age as the rubber looks weathered and dry. Surprisingly the driveshaft and the splines look good, no rust and well lubed. I guess the bike has not been ridden in inclement weather much.
I didn’t have the white grease that BMW recommends to waterproof the boot and instead I used Wurth silicone paste as it’s thick and tacky. I will see how it holds up in few months.

 

[fantastic]

Maybe the make a rubber coating spray to keep rubber pliable? Short of using grease I suppose. Those BMW's are nice looking bikes.

 

[KrisZ]

Maybe the make a rubber coating spray to keep rubber pliable? Short of using grease I suppose. Those BMW's are nice looking bikes.

20 years is not too bad. Not sure if any rubber treatment would’ve extended it, perhaps.

That paralever shaft system is neat for sure. As far as I can tell there is no shaft jacking on hard acceleration like in a traditional motorcycle shaft systems.

 

[fantastic]

20 years is not too bad. Not sure if any rubber treatment would’ve extended it, perhaps.

That paralever shaft system is neat for sure. As far as I can tell there is no shaft jacking on hard acceleration like in a traditional motorcycle shaft systems.

You have a point about good lifespan and I'll take a shaft drive w/boot replacement over a rubber belt anyday. It's that time of year to get out and ride but maintenance first though lol.

 

[Ausfahrt]

You have a point about good lifespan and I'll take a shaft drive w/boot replacement over a rubber belt anyday. It's that time of year to get out and ride but maintenance first though lol.

Nothing lasts forever but belts are much cheaper and easier to replace than final drives.

 

[fantastic]

Pro's & con's for sure & lower cost is something one must consider. I heard too many times other riders getting a rock in the belt then needing to replace it as one example. Although it may be cheaper & easier one may have to do it more often than shaft. I've also met other folks that seemed happy with them but not sure if they've ever owned a shaft or not. That gear oil looks toasted! Do you know how long it lasted?

 

[Ausfahrt]

Pro's & con's for sure & lower cost is something one must consider. I heard too many times other riders getting a rock in the belt then needing to replace it as one example. Although it may be cheaper & easier one may have to do it more often than shaft. I've also met other folks that seemed happy with them but not sure if they've ever owned a shaft or not. That gear oil looks toasted! Do you know how long it lasted?

BMW at one point touted the final drive fluid as 'lifetime' fluid but we all know that can't work. The FD is a low volume but high stress and heat application. The common consensus now is to change the FD fluid every 12,000 miles and I just do it every second rear tire.

The FD pictured is from my '07 GSA and it failed at 68,000 miles. The phasing is critical on these and the factory doesn't always get it right. A replacement unit from BMW was $3500 if I recall correctly so I opted to ship it to a well respected independent BMW motorcycle shop in Virginia to have it rebuilt for $900.

The fluid pictured was toast and had lots of sparkles. It was not exhibiting any signs of failure yet but I monitor the FD temp with a cheap infra red gun from Harbor Freight and noticed that it was running about 20 degrees higher than normal after a high speed ride. Since the rebuild I have been using Redline Shockproof gear oil and I now have 102,000 miles on the bike.

 

[KrisZ]

Pros and cons indeed. Belts are great for low HP applications. I’m surprised that in reality only Harley is using them. A lot of the “commuter” bikes should use them instead of chains.

I like chains for the simple fact that changing the final drive ratio is super easy. If you commute, put a smaller rear sprocket to lower the RPMs. You want more grunt, put a bigger one. Super easy and cheap.

Drive shafts are the most complex, but in theory should last as long as the rest of the bike and are low maintenance. Good for putting a lot of miles without much hassle.

 

[fantastic]

BMW at one point touted the final drive fluid as 'lifetime' fluid but we all know that can't work. The FD is a low volume but high stress and heat application. The common consensus now is to change the FD fluid every 12,000 miles and I just do it every second rear tire.

The FD pictured is from my '07 GSA and it failed at 68,000 miles. The phasing is critical on these and the factory doesn't always get it right. A replacement unit from BMW was $3500 if I recall correctly so I opted to ship it to a well respected independent BMW motorcycle shop in Virginia to have it rebuilt for $900.

The fluid pictured was toast and had lots of sparkles. It was not exhibiting any signs of failure yet but I monitor the FD temp with a cheap infra red gun from Harbor Freight and noticed that it was running about 20 degrees higher than normal after a high speed ride. Since the rebuild I have been using Redline Shockproof gear oil and I now have 102,000 miles on the bike.

Excellent workaround to limit the $3.5k cost. Redline having a good sales year It seems I'm hearing more & more buying their products. Good fluid goes a long way. I've used a thermal gun to check wheel bearing temps before & sounds like it came in handy for you.