Hey Guys,

I was wondering when I should get the fluid for my front and rear differentials changed?

Some background:
My D is a 2001 4.7 V8 AWD w/ tow package.
I had it last done Nov 2009 at 158,500mi and right now it’s at 177,000mi (18,500mi difference).
It was replaced with Mobil1 75W90 in the front and 75W140 in the rear.
I do a mix of highway and city driving but no off-road and no towing; only had to use 4HI 3 times during snow emergencies.
Thanks in advanced!

 

Change it every 30k miles for best results and 60k for not as great results but still in manufactures specifications.


If you use Fully Synthetic (which it sounds like it is) you should have no issue going to 60k however I would still pull it at 30k. Also be aware if you tow a lot then you should replace it at 15k intervals and use Fully Synthetic (well I use it either way).

 

Also, if you have a limited slip rear diff, don't forget the friction modifier.