Originally Posted by dc lindberg
How did it end?
Sorry, Albert, I've only just seen your post.
Yes, all done and dusted. I borrowed all the tools from the BMW Club, it was so nice to have the correct ones and not have to resort to making do.
As it happened all their measuring plates were out on loan but I was offered an old one that was supposed to have something not quite right with it, but the Tool Hire Secretary didn't know what exactly, as I have the dimensions for the plate (thank you Joerg) I could check it before using it so I went ahead and used it.
All seemed OK with the plate apart from the clearance around the bearings, from memory they were three thou (that's IMPERIAL, I'm still in the dark ages and so still not used to metric) larger than the bearing outer races. In fact this clearance was in accordance with Joerg's drawing but I found it to be very inconvenient because it allowed the outer race to tip while measuring the protrusion of the bearings through the plate. I managed to get around that by putting a dial gauge (dti) bearing lightly on one side of the protruding race to ensure that it didn't tip up (or, more to the point, to make sure that I wasn't pushing the side I was measuring down) before measuring on the side opposite with a depth micrometer bridgeing two hardened steel parallels. I took photos of the setup but although the pictures display OK on the camera screen I can't download them to the computer. It's a fault on this particular memory card, I'll try and post them ASAP if I can get it sorted.
For that reason I would be very interested to know what is the size of the three large bored holes in the plate for the bearings in a factory supplied
measuring plate if anyone can help, I would be interested to know whether the bearings are held snugly enough in the bores so as not to tip when measured.
Anyway, after taking dozens of measurements and averaging them out I found that the shimming would be identical for two of the new bearings and the other one should have the 0.38mm + 0.28mm instead of the 0.20mm + 0.50mm shims. On reflection, considering that I hadn't replaced any of the shafts, I decided not to change the shimming and left them as they were, the truth is that bearings are manufactured to a precision way, way beyond my ability to measure so any variation in the bearings themselves would be negligible.
All that was about 3,000 miles ago and there have been no problems, it changes gear just like before- no better or worse, but the noise has gone.
Oh, the reason for the original noise was that the front end of the output shaft bearing had broken up, if I can I'll post a photo of that too in due course. I replaced all six bearings though, it seemed silly not to.