I think parts probably could be found, but a complete rebuild is an expensive ordeal. If it were mine, I would look around for a used one with less slack and drive this one in the meantime. Used 2 ton farm trucks can often be bought for less than a rear end rebuild, and then you would have a bunch of spare parts. 46 through 51 uses the same third member. 52 and 53 can be made to work with changing side gears.