Fixing a leaky brake pivot in a BMW final drive.

Old BMW motorcycles can leak oil from the final drive unit through the rear brake cam pivot. The spindle runs directly in the alloy castings & wear in the bore means that the O-rings on the spindle no longer do their job. One way of fixing this problem is to bore out the drive casing & brake backplate & install a steel sleeve right through the whole unit. Someone had tried to do this to the unit seen here, but messed up the boring operation. That gave our customer the opportunity to have us rebore & fit a bush in the brake backplate which he could then fit on his R65. We had already modified the brake spindle on that bike to take extra O-rings on the outer end which stopped the oil leak on that side. He was still getting oil leaking onto the brake though & really needed that fixed!
Machines used in this video -
Beaver VBRP milling machine
Smart & Brown model "A" lathe

[@chrisstephens6673]

"Oh how the mighty have fallen " Earlier years did not have the need for o rings as the cam pivot bushing was continuous. I could be wrong but i think that is possibly series 7 800 or 1000 but that is just being pedantic on my part😉

[@MidEngineering]

Customer said it was an R90 case to go on his R65 so I guess late 70's, early 80's. No idea what series that would be. I don't know too much about BMWs!

[@philipjackson5818]

The sleeve should be an interference fit, you have to warm the case up to install it.

[@MidEngineering]

Like I did in the video...!