My suspicion is that I did not pound the side axle shafts in far enough during reassembly. (In fact, I didn't end up pounding them in at all. Just used hand pressure.) Would that be a reason for the leak? As far as I can see the seal has a little "mouth" that comes out and I'd imagine if I didn't push the shafts in far enough there would be a gap between the "lips" of the seal and the shaft housing. Here's some current on car pics of the gap between the shaft and the diff housing. Let me know if you think I still have a mm or so left to go.
