Looking to change the front and rear diff, and transfer case fluid in the next couple weeks, I know im early but i like the idea of fresh fluid, Looking online for a retailer i am noticing that the Rear Diff fluid is a rare product. SAE 75w-85 Synthetic. The 80w-90 for the front is much more common.. These #'s come from here

6.7L Power Stroke Maintenance Schedule & Service Information

Anyone got a link to online retailer for their Fluids?
Is there a Gasket recommended for the Diff covers?

Thanks!

 

When I did my front + rear diff and transfer case on my 2008 F-350, I used all AMSOIL synthetic.

I made my own gaskets with gasket maker since they don't make a seal. You can call ford and see if they make one for the newer trucks.

Get yourself a small hand pump for the transfer case. Works wonders when your laying under there.

matt

 

The rear axle fluid viscosity depends on which axle you have. I have the Data M275 and the viscosity for that is 75w-140 (same for the M300). All other rear axles use 75w-85, which I agree is an odd duck. If your oil manufacturer of choice doesn't carry that exact viscosity then get something close. For example, AMSOil has 75w-90.

All viscosity info is based on the 2017 Owner's manual, version 3.

 

Just did my rear diff yesterday (F250 sterling axle). I used the 75w-85 Motorcraft stuff. One thing I'll note, the owners manual states 3.3-3.5 quarts. I only got 3 qts in when fluid starting overflowing out the fill hole. I might have got just a bit more than 3 qts. I tried to get as much old stuff out too, including the cavities at the bottom of the diff.

 

Just get the Motorcraft stuff. No?

 

I'll say yes. It's actually really good stuff. I paid a little less at a dealer.