This is a brief description of how to shim your diffs. I'll do my best to give you a step by step description of each picture.
Here is a picture of the diff. and the shims I use.
Remove the 4 screws shown in this picture
Separate the cases
Remove this gear
Place shims on the shaft as shown. I usually start with 1 or 2 shims.
Slide the shims all the way down until they are against the gear.
Insert the gear back into the housing
Put the cases back together and insert the 4 screws
Check for slop by trying to move the shaft on the left in and out. If it feels snug, check for binding by rotating it. If it all feels good, your done. If it feels sloppy, add another shim. You want it to move as little as possible in and out, while still rotating freely.
Hopefull this post helps those of you with questions on how to shim the diff. I'm not a pro by any means, this is just the method I use.