I have a 52' torque tube. I pulled the outer axle bearing and seal and there was shim amongst the bearing and seal, but I do not recall the order of how they were arranged upon removal. The "Book" says that it is there to establish a maximum gap of .014" between the end of the axle shaft and the "block spacer" in the center of the differential.
I am guessing that it goes between the seal and the wheel bearing.
