Opinion- Driveshaft Bad ?

[mtrewartha]

Hi all-
I'm new to being a BMW Bike owner. I bought an 87 K100RT. Upon digging in the forums and reading about "The Spline Lube", I figured I would give it a shot. Took off the Final Drive and my jaw dropped upon seeing the Driveshaft. I am not even to the object of my project.
I would like to verify that this needs to be changed from some experienced K owners.

Thanks

 

[jdiaz]

Yep, you need a new one!

 

[mieczkow]

Yikes!



That's a pretty bad one - you should be able to find a good salvage rear unit for not too much money. Check the IBWR parts section and the flea market on the forum. You can also post a "parts wanted" on the IBMWR site for free.

 

[AntonLargiader]

It's pretty much toast. What do the mating splines on the pinion look like?

 

[cayuse60]

http://www.beemerboneyard.com/fidrun.html

checked the boneyard...all sold. I just bought one from a 90 K75 off ebay for under $120.00...spline looked good in close up pictures.

The above link allows you to request used parts and they will contact you, but they are not cheap.

 

[mtrewartha]

Mating Splines?

The mating splines actually look pretty good. I could probably use some opinions on that also. I will try and post a pic in the next day or two.
Thanks all for your help.

 

[mtrewartha]

Mating Splines on Final Drive

Ok- I had responded that they looked "pretty Good".
Upon looking at other posts and info, I am not so sure. Here is the pic.
Any opinions appreciated.

 

[98lee]

Yep, Those are trashed! When you replace them, you should replace them both at the same time(driveshaft and final drive). Otherwise the worn spline will accelerate the wear on the new spline.

There are two companies, one in Oregon http://www.hansensmc.com/spline.html and one in Canada http://www.brunos.us/ that will repair the final drive splines. The one in Oregon requires that you buy a new driveshaft. The one in Canada has a repair for the driveshaft as well.

I bought a final drive off ebay with perfect splines for less than the cost of the final drive repair. But you have to REALLY examine the photos of the splines for nice crisp
square splines with no tapering and be sure it is the proper gear ratio.

Good final drives sell for less than $200. But good drive shafts are rarer than hen's teeth and sell for way too much (over $150) so I went to chicagobmwmotorcyle.com and bought a new one for $228 (list $285. They give %20 off on all parts)

 

[mtrewartha]

Yep- those are trashed

Thanks Lee- http://forums.bmwmoa.org/images/smilies/dunno.gif

 

[98lee]

Mark,

If you go the NEW driveshaft route, see my recent post on driveshafts.

If you go the used route, make sure you get the 20 spline shaft and final drive. Early K100s (before '86) had 16 splines. you don't want those.

I'm not sure what year they upgraded the universal in the driveshaft, but if you get a newer used driveshaft, you might have the same issue that I had with may new one, but no big deal.