I was wondering when to change the oil on my transmission and front and rear differential on my pickup. My friend told me to change it about every 30,000 miles. So, if someone could tell me how often you change your transmission and front and rear differential oil I would appreciate it. Thank you.

 

I change my manual transmission and rear-end oil every 30,000 miles. I use Royal Purple Max ATF for the trans, and Royal Purple 75W-140 for the rear-end along with 4oz. of Ford friction modifier since I have the 3.55 Limited Slip.