R60/5 rebuild nears completion – with some puzzles. . .

[Bill Harris]

Interesting demo of the shift dogs.

Odd about the first gear bushing running tight. I can't remember much about those bushings. Not surprising about their cost, though. The fit a gearbox that's been out of production for 40 years and nothing else. The bearings have many other applications.

--Bill

[Tin Woodman]

Turns out the binding of first gear was caused by good ol' fashioned friction - new first gear bushing was too wide and old one was too narrow. I believe when the transmission was last rebuilt, one step was overlooked. It explains why many parts including all the bearings, are good. I'll explain. When I removed first gear I didn't notice the thrust washer showed signs of heat (notice the blue marks.)



When the gear was on the shaft, the original bushing was just barely proud of the gear surface.



When the ball bearing was pressed on, it applied too much pressure to the thrust washer with the resulting wear -



I'm sure what some of that 'magnet plug fuzz' is. Put a new bushing on with lots of clearance -



Unfortunately, too much clearance -





Either the bushing I installed is the wrong part (according to the fiche, it's correct), or the I have a version of the tranny with a thinner first gear (doubt that's the case). Will check with my parts supplier next week.



This all began when I started doing the calculations for shimming the shafts and discovered this discrepancy. The manual (and BMW, for that matter) don't provide specifications for bushings and the bushing for 2nd and 3rd gear is not user serviceable.

Good point, Bill, about these parts. When I said, 'I picked up a couple of bushings', I really meant I paid for two with one still to come on back order - arrival status is 'indefinite'. I'm not complaining - I was already warned not to venture into transmission repair.

[Bill Harris]

Good job of sleuthing.

The parts availability is one reason I'm farming out the next rebuild/refresh of my transmission to someone who is a master. They'll have donor boxes and/or know how to source these obscure parts. I'll gladly pay for someone's headache...

--Bill

[disston]

I hope you do a 5 speed some day. But the 4 speed is entertaining. Nice to compare the differences I guess.

I wonder if we aren't supposed to just make our own bushings? This doable and quit simple if you have a lathe I think.

[Tin Woodman]

Originally Posted by disston

I wonder if we aren't supposed to just make our own bushings? This doable and quit simple if you have a lathe I think.

For a while, I was wondering the same thing until I realized the spiral oil channel on the OD limits how much material can be removed. I'm thinking the wrong part got into my suppliers' parts bin.

Originally Posted by Bill Harris

Good job of sleuthing.

The parts availability is one reason I'm farming out the next rebuild/refresh of my transmission to someone who is a master. They'll have donor boxes and/or know how to source these obscure parts. I'll gladly pay for someone's headache...

--Bill

Quite agree but I think the biggest challenge in doing your own transmission repair is getting the output flange off (and back on again).



(photo used with permission of Joerg Hau)