I have gotten several different thickness' of gaskets and they were of different color, whether they were meant to be that way or not is another matter getting them from different source's, the shim is in there from the factory if it needs it, I have rebuilt some that did not have it, chances are if the case haves go all the way together the bearings are worn and probably need replacing, That is all I'm saying and Did I mention I hate typing and trying to keep my answers short until a long winded sucker comes along! Lol.