I have a 95 F250 7.3 turbodiesel 4x4 with a manual transmission. I would like to change the fluid in the transfer case and in both the front and rear differentials. I would appreciate any recommendation on type-of fluid and quantity, along with any tips on performing a smooth change.

Thank you

 

Transfer case takes ATF. Aprx. 2 quarts, IIRC. Like any bath oiled case, you fill it to the bottom of the fill plug. There's a fill plug and a drain plug. Don't overtighten either one (don't ask how I know .

Diffs take any good quality gear oil; synthetic is always a good choice. If the rear is limited slip (axle code C5 or C9), it should get a friction modifier additive; however, synthetic gear oil typically doesn't require the additive.

Rear diff, you loosen the cover bolts a little, loosen the LOWER bolts a little more, put a WIDE pan under it, pull the bottom edge outward a little bit 'til it drains. Fill plug is on the forward side of the diff.

Front diff, you either have to take the whole front axle apart (since the one "arm" doubles as the diff cover) or siphon it out through the fill hole.

 

I bought a few quarts of Mercon V automatic transmission fluid at the local ford dealership here. I assume this is the best stuff to use, and if I have any extra I would like to add to the manual transmission if it will work?

 

Transmission REQUIRES synthetic ATF.

 

Thank you for the response. Can you recommend a good brand? I found this one: Castrol-Transmax-ATF-full-synthetic-multi-vehicle-transmission-fluid on A-Zone's website but it doesn't seem to fit with Mercon V; the fluid says it's compatible with Mercon LV.

On another note, I stopped at my local Ford dealership a couple of days ago and gave the rep all of the specs of my vehicle. He came back with the Mercon V ATF saying it was appropriate for use as fluid on the manual transmission of my 7.3; it seems he was full-of-it and that is a little disturbing.

Thank you for the help