My co-workers were a bit surprised when I told them my Camry ('96, '99) takes ATF fluid in the differential. They said they would think it would take gear oil, since the diff does a lot of hard work, to extend the life of the differential gears.
Then again, one of these co-workers has a Dodge, and enjoys pushing the metal to its limits. He uses 10W40 for his oil, saying this thicker oil reduces wear.
Any thoughts on this? Would it be advisable to add 10% or so heavy gear oil to the differential oil? Or is this just not a problem with the Camry?
I'm at 74k miles on the '99, and 139k miles on my '96.
Michael