Gearbox for R65.

[Beemerboff]

Thanks for the replies guys.

We are covering new ground here, as AFIK none of the gearbox rebuild blogs, or threads, or my Haynes, cover stripping this shaft.

The box is a 85 Mono G/S without any circlips on the output shaft.

My input roller track had a couple of what looked like scores on one end, but it measured up OK - so I polished it up with fine brown Scotchbrite and the scores, or streaks, have gone.

It might only have been a bit aluminium swarf which was streaked round the race.

So I will wait and see how the new roller bearing outer fits before I start pulling the shaft apart. There was no noticeable play in the shaft before I stripped it but the loose bearing rocks on the shaft , at both the rear portion that the rollers dont run on, and the nose where it does.

The shaft rear seal was leaking and I would like to replace it, so I will order a couple so I get a bit practice.

Just bought a Ex Oz army Yamaha XT600 to keep the dirt/ off road side of my riding moving as this is spring and the prime riding season.

They are being auction off and the bikes, which have the big Acerbis tank and a huge rack and soft pannier frames, are selling for not much more than the tanks go for on Ebay.

 

[Gil]

Gearbox shimming

Great gearbox writeup, very useful. My bearings are all notchy so I'm glad I opened it. The main aim is to fit one of those longer fifth gears, to account for using a 17" paralever rear rim on my G/S. Perhaps an obvious question but is it always necessary to check the endfloat rather than just assuming that the previous setup of correct? Also, I have some pitting on the input helical gear. How bad does this have to be before needing replacement? Once again brilliant writeup.

 

[Rob Farmer]

The likelihood is that the shims will all fall into the gearbox when you remove the cover so you'll end up shimming them anyway.

 

[Weekday Rider]

Mike Fishwick of the BMW club kindly rebuilt me R65LS gearbox when the dreaded spring broke (German engineering, not at it's best). After the rebuild I had a gearbox that was so sweet I can't describe it. The broken spring was replaced with a Bob Heath (I think) spring and the gearbox ran sweet until I sold it many thousands of miles later.

I was shown many times, in slow motion, how to reassemble the box ie dropping the gears and bibs and bobs in but, I'll stick to what I know as I couldn't get it at all. Good luck with your rebuild, my advise would be to give it to someone who can not only do it but enjoys it. Mike, if you are reading this thank you again. Jim.

 

[Beemerboff]

Gil - one of the roller bearings is larger than the others and should also also a special high capacity bearing. made of special steel.
Not even BMW always supply the correct bearing, although recent supplies are reputed to be the correct one again.
Richie Moore is in contact with the factory and has details of the correct bearing, and he also has the current recommendations on end float, some other box rebuilders are reluctant to even acknowledge the existence of either.
If you intend fitting aftermarket gears check the dimensions carefully, as some are a long way out from OEM and will have you rebuilding your box in 20,000 km.
Again RM sees to be one of the few who checks everything he receives and has picked up faults withitems like OEM camshafts and oil pumps so he will know who supplies good, er, gear.