Terry,

When I replaced mine I bought the bearings from Clausing as a match set.
There was no shim needed/supplied). When I installed them I realized
there was two ways to do it. I mounted them so that when they were
mounted on the spindle they were "tight". I don't remember if I ever
figured out if this was the official direction or not, but I never had
any problems. This way make since to me because the spindle nut has a
locking feature, and the retaining nut does not. If the nut backs off,
then you have lost the preload (bad thing).

I did have a heating problem, but that was because I filled the bears
completely with grease, and at the 2 highest speeds things over heated.
Found out later that you should fill the bearings 1/3 rd with grease.
Once I removed most of the grease it ran fine. You do this by filling
1/3 rd of the bearing 100% with grease, and then spinning the bearing
around until it's even.

Hope this helps,

Vince



Terry Keeley wrote:
I'm restoring my 1963 Clausing 8520 mill ( pictures here if interested
http://gallery.intlwaters.com/thumbnails.php?album=323 )
and in the process am replacing the spindle bearings. I've read through
many posts on the Yahoo Group and have just gotten more confused.
Talked to a few bearing "engineers" (ya right) at SKF and they don't seem to
have solid answers either.

The spindle takes a pair of 7205 angular contact bearings that are held in
place by a locking washer and nut. I was able to find on the MRC site that
the torque on the nut should be 23-50 ft-lb. but can't seem to find answers
to the following:

Should the bearings be mounted "face to face" (where the contact lines of
the bearings converge inward), or "back to back"?

I can order bearings that are ground and sold as a matching set in either "b
to b" or "f to f" that when mounted together and the retaining nut tightened
give a "light preload".

I can also order bearings that are not matched but are for "universal
pairing" that are about half the cost and are made to mount either way.
Some posts on the Yahoo Group mention that to apply a preload to these
bearings a shim is needed between them either on the inner or outer race,
others say none is needed. If the bearings are made to mount either way how
can they be preloaded without the use of a shim? If needed how thick should
it be?

The machine came fitted with standard bearings and no shims so I can't go by
what was there.

Any experts here? Thanks in advance!