Well , I don't know if it is me , or luck of the draw , or ??? But this year I have had the gear box's in two BMW's go out . My '02 K1200LT , & my '95 R1100GS . My LT's clutch started slipping a little , a few miles before I got the dealer to take a 2010 R1200GS Adventure for a test ride . I had put a new clutch & a bunch of stuff in it last year , & had drilled the slave cylinder & the bell housing . Well it was leaking gear oil out the bell housing , but I thought it would make the ride home...Not ... It did make it half way , & all was fine . Then it went into total slip . I nursed it off the expressway in first gear , but it would slip real bad if you gave it any gas . It was a long day before I got it home . It was a good thing I had a fiend riding along that baled me out .
Anyway , at the time I had my R1100GS on my lift ,& was in the middle of replacing the rear main crankshaft seal on it ( third try ) ....Well ...Turns out , as I was doing the crank shaft seal ...I found the crank seal was OK , but the input shaft seal on the gear box was leaking . I thought with the leaking input shaft seal , I should take the spring & boot off the back of the gear box & have a look at that seal too . I then found with the spring off you could move the input shake 1.5 MM . The GS had 59,000 miles on it , and the gear box had the original tapered roller bearings on the input shaft . BMW has changed to a new " clean bearing ", & to put them in you need to re-shim the input shaft . So I took the gear box over to the dealer , & had them do it . They put the input shaft bearings in, re-shimmed it , and also put one bearing on the output shaft + 3 seals . On a side note , my wife thought I needed a new GS , so after I got the '95 put back together I traded it in on the 2010 R1200GS Adventure .
Well , My LT only has around 40,000 miles on it ... But I found as I drained the gear oil out of it as I was tearing the bike down . it had what looked like a bearing retainer & one of the two split washers off the input shaft stuck on the drain plug magnet . It looks like the input shaft is shot on it too , I can moved around probable 1.5 - 2 MM . Also the clutch rod /clutch cover clutch disk , pressure plate , & Diaphram spring were chewed up . I got a used gear box to put back it , but I am going to see if I can't take the gear box a part to have a look see.
Anyway , back to were I started , was it me , or ??? . I am not trying to start an oil thread , but I was using Royal Purple 75W90 gear oil in both gear boxes , could that have been part of the problem ??? Maybe it was just a little too thin ??? Maybe it had nothing to do with it . What do you think ..Thanks