Differential problem with a 2010 Toyota HiAce

This hasn’t surfaced as a common problem, but that doesn’t mean it isn’t happening in some instances. The HiAce rear axle should have seals on the actual differential centre as well as each axle. If these are failing continuously, there are a number of possibilities.

The first is that there’s something bent or damaged that is placing undue force or damaging the seal, causing it to fail prematurely. The second is that the seal (and its replacements) are from a dud batch of seals with either poor manufacturing tolerances or a flaw in the material from which they’re made. The third culprit would be a blocked differential breather which is not allowing the pressure inside the housing escape, and that pressure is causing the oil to be pushed out past the seals.