I plan to just swap out the entire axle assembly, housing and all, I'm sorry if I wasn't clear about that in the beginning. That's why I got a bit confused by your original answer. On the part I'm looking at, all I'll need to do is rebuild the brake cyclinders and install new shoes and in it goes as far as I can tell.

As for my current axle, it was sloppy when I bought it, I don't think it's got any worse, I'm just tired of the problems it causes when I'm towing. Why it's that way is probably due to the mileage (120K). It probably has about 10 degress of free play, maybe less. Just the clunk typical of older Fords I guess.