Gearbox bearing replacement

[John Roberts]

My problem is how to measure how much the bearings protrude through the bearing support plate (sorry,I just can't remember what it's called- it's that plate you use to find what shims you need for the g'box bearings.)

I did this job some years ago and had great difficulty in measuring how much the outer races stuck out because they tipped over so easily while using the micrometer on them.

One point that might be relevant is that the plate itself was a one-off, I don't know who made it but it wasn't a commercial item, and that there was a clearance of two thous, (0.002") between the outer races and the holes in the plate, allowing them to tip when trying to measure how much they stuck out. Can somebody confirm that this is normal or should there be a snug fit that prevents tipping.

The tools I used were a pair of ground parallels and a depth micrometer, and despite trying to use the lightest touch possible I found it impossible not to tip the outer race.

So, any tips, please, gentlemen?

 

[B Murr]

I've seen those ground parallels for sale. There's a shim plate you can get which presumably will hold the races in place and prevent tipping. Might even be someone here who lives near you that would be generous enough to lend you such a plate. I'm sure a quick search of Google will reveal who sells them, there is a German website that supplies them and some OEM tools too such as pinion bearing pullers etc.

 

[DrFarkoff]

http://www.cycleworks.net/index.php?main_page=product_info&products_id=39

 

[Garry H]

This I what I use works a treat
If you can find a scrap end casing and modify it a bit

<a href="http://s168.photobucket.com/user/pbgaza/media/interesting/box3Medium.jpg.html" target="_blank"><img src="http://i168.photobucket.com/albums/u181/pbgaza/interesting/box3Medium.jpg" border="0" alt=" photo box3Medium.jpg"/></a>

 

[B Murr]

Here's the plate for a very reasonable €50 http://www.bmwboxersupplies.com/gearbox-clearance-plate-p-68.html