extremely common for me unfortunately. I just re-secured my driver side auto hub for the 100th time (it seems) last weekend. Heard some metal to metal action down there and yanked that hub cover off. Found the c-clip and three washers all tangled up inside there. I've had this truck (91) for about 6 years now and have replaced both sides at least 2-3 times per side. But see, I'm an idiot. I replace them with a cleaned up version of the same hub. Duuh. Well because that's what I have laying around. I remember the chap that sold this truck to me woudln't let me take it until he "fixes that front hub". At the time I had no idea what he was talking about and thought it was nice of him to do so. You have to have the exact amount of "play" in the axle which mean the exact number of shims that are an exact thickness. Sticking one or two on there to take up space or using a prybar to get that sumbitch as tight as possible before you squeeze that c-clip on are both bad ideas. Manual hubs. Good choice. Much stronger too (from what I hear). I'm kinda slow to catch up sometimes.