Hello all, I am refurbishing a '90 K75C. In the process I took the fork tubes out for inspection and had to replace the tube itself on one side due to rust pitting. These are the "SPORT" tubes marked with an "S" stamped into the top of the tube. Now I'm re-installing them and didn't mark which is left and which is right. Apparently that makes a difference as there are different amounts of fork oil in the left and right. S.F. BMW shop foreman told me that one fork tube handles compression and the other rebound. But he couldn't tell me how to tell them apart. Does anyone know if there is a way to do so? Particularly without tearing them down again?

My fall back approach will be to use the same amount of fork oil in both. Given the age and wear, 47K miles, it may not make any appreciable difference. But I thought that I would at least attempt to be correct. And yes Haynes does say to refurbish them one at a time so as to keep this from happening.

280ml both sides the only forks that have differing quantities are K1100 RS/LT

Items 6 is RH side, item 12 is LH side. 13 thru 16 being the valve, there's hardly a difference.

As Rick says, 280cc of oil per leg is the requirement. I use 5W to keep the ride supple, but 7.5W to 10W will do for a firmer ride or a big bloke.

Link: http://realoem.com/bmw/showparts.do?model=0503&mospid=51751&btnr=31_0369&hg=31&fg=42

Thanks, I didn't suss out the differences in the micro fiche images. Based on that and the photos I took during the refurbishing I do believe I was working on the right hand side. That and I don't remember or find the parts 13-16 in the photos. Now I just need to go out and reverse placement of the tubes in the forks.   No biggee but nice to think I've got it right.

Will also just go for the same fluid in both sides.
Thanks guys