rear differential capacity - Diesel Forum

superstinker · 09-13-2009, 01:21 PM

hi iwas wondering if anyone could tell me what the rear diff capacity is on a 04 f350 dually with a 4 10 gear and what grade gear oil do you put in? thx in advance

GrampyJim · 09-13-2009, 02:52 PM

About 3 quarts of 75W140... If it is a limited slip, you'll probably need "skunk oil" (friction modifier) depending on your oil selection.

novimustang · 09-13-2009, 08:59 PM

Before I did my rear diff service I found a few different suggestions for how much, so I suppose it can vary somewhat, but I bought 5 qts of Royal Purple 75W90 and it took about 4.5. Make sure when you drain it, you get some shop rags and soak up the fluid that sits in the bottom of the carrier - it won't drain out on its own. I actually was gonna use RP 75W140 - that's what I TOLD Autozone to order, but they ended up getting the 75W90 and I don't complain and I didn't care that much so I just used it. In my opinion, unless you live and tow in extremely hot areas, I don't think it really matters all that much. I'll probably use the 75W140 next time I do it, but just because I guess.

novimustang · 09-13-2009, 09:00 PM

oh yeah the RP doesn't require any additional friction modifier.