[Tom Kirkham]

There is no spec per say. The bearing spacers are cut to fit to get the right preload. You said that you have a spacer that has disintegrated. I would bet that you meant shim. Do nut use shims they will disintegrate. Anyways what you need is a hardened spacer that is cut to fit. We had a whole stack of different size spacers so we could find the right dimension quickly. We then would make a hardened spacer on the lathe. If the spacer is not hardened the bearing will wear into the spacer and you will lose your preload. We were torquing the bolt to 150 ft-lbs. You also need to inspect the washer to make sure it is not dished. To set the preload we just used a press. It takes way to much time to put the bolt in and out to get the proper set up. Also be sure and Loctite the bolt. Now you know why we went to the Porsche bearing.