Re: other source of water entry into drive...
What Don S said: Upper to lower oil passage seal, waterpump base gasket and oring, Driveshaft Oring and waterpump seal, shift shaft seal, propshaft seal, bearing carrier seal. My experience has shown that the leaks I have had were due to waterpump-related seals (driveshaft seal, orings, gaskets). Luckily, they are the easiest (and cheapest) to replace.d
