Yea, if you're in Phoenix it's one of the few major cities hotter than here (Las Vegas)..Think Tucson is about the same temps as Vegas...Pound the seal out w/a screwdriver and/or seal removal tool then look carefully at the ext housing's seal bore...My guess is that it's worn, out-of-round, etc and just needs RTV on the seal and bore to prevent leaks. You can do this regardless of whether it's actually coming from the bottom or just appears to be (you do have to get underneath to verify, hard to do otherwise. As mentioned, look at the slip yoke for grooves cut into it...Replace the yoke if so...
