[Hi Volt]

You may want to consider inspecting the retaining collars for the axle bearings. These should always be replaced new when doing bearings. In addition to retaining the bearing, these are essencially the second part for the axle seal ( not the axle surface itself ). Any wear groove or damage to the surface of the retainer will compromise the seal. If a shop is not careful to preheat the retainers before pressing into place, using excess force can cause edge damage that can score a new seal when the axle is re-inserted.

Also check to make sure your vent on the diff housing is not clogged as built up pressure can cause oil to be pushed past the seals.