Last year, i bought a KTRE 12 bolt, i know they aren't as good as other rears, but i got a good deal on it. So having the guy install it, he has to put new axles in it and convert it over so it would be a 4 channel for my car. But here is the thing, When i get it home it is leaking by where the drive shaft bolts up to the rear end. I call the installer and he says bring it in so i can put a new pinion seal in it. So he puts a new seal in it, but it still leaks. It isn't a small leak either, in five minutes of parking it at the house, it has a spot the size of a 50 cent peice. I did a search, but i didn't really find what i was looking for. So any help would be greatly appreciated.
You may need him to go through the rear and check the preload on the pinion bearings and maybe make an adjustment. If the preload was not set properly then changing the seal is worthless if there is a solid spacer in there. Have him double check and see if the seal is leaking around the housing and not the seal to the yoke.