I have a 07 Avalanche LT Z71 that has a leaking pinion seal. No big deal, bought a new seal, put it in and the fluid just runs right out. The old seal did not have a lip and was flush with the casing, the new one has a flange? Were there different seals for the 2007 Avalanche. It's 5.3L V* Flex mag in Mexico 12 bolts on the inspection cover.