I had my gear/diff oil changed at around 40,000 miles. I'm at around 80,000 miles now. Should I have it changed again soon?

I see the normal maintainence schedule says do it every 60,000 miles, the other schedule says every 30,000 miles... but I also know the people here often know better than the "official" recommendations

Are there any noticeable advantages to changing it? Does it lessen that "rallycar" whine any?

I have no complaints otherwise, no problems shifting or anything. But I also don't want to be hurting anything by waiting too long

 

You don't have to change it but if it were my car I would. Using a higher quality synthetic for the tranny CAN quiet it down a little but it's not a guaranteed thing. I say throw some Redline in the tranny and rear diff and find out.

 

I change mine every year. and I beat the crap outa my car (shhhhh)

no issue

it takes 1 hour-ish to change it myself. doesn't hurt me.

 

The frequency of rear diff oil change depends on how the car is used. Lots of turns/stop and go traffic means more stress on the diff, which require more frequent changes.

You can't hurt it by changing more often than not.