tranny and diff oil change

[lariat 7.3]

whats the best oil for the tranny? how much does it take? whats the procedure? also whats the best oil for the diff's front and rear? how much do they take?

[Mark Kovalsky]

Here's how to do the trans:

Changing ATF: 7.3L PowerStroke Engine and 4R100 Automatic Transmission.

I like Mobil 1 synthetic ATF.

[txfxl]

someone else will chime in with the specs, i just did the diff and got some good advice here, its a few pages back, thread is titled "which rear diff fluid to use" or something.

my one bit of advice is make sure you have a pump to get the fluid into the pumpkin, the fill hole is in the absolute worst place ever

[SmokeyWren]

Originally Posted by lariat 7.3

also whats the best oil for the diff's front and rear?

The rear diff requires 75w140 synthetic diff lube. All the synthetic oil folks make it, including RedLine, Royal Purple, Amsoil, and Mobil 1. The Ford dealer has it in a Motorcraft wrapper for around $20 per quart. I bought the house brand at Wal-Mart, SuperTech or some such, for around $10 per quart. Good stuff.

The front diff requires SAE 90 or 80w-90 "premium" diff lube. I'm pretty sure that "premium" means synthetic. Your Owner's Guide probably says 75w90 but that has changed since that guide was printed.

how much do they take?

Almost four quarts for the rear diff. For the front axle, it depends. Almost two quarts for the Dana 50 front axle, or almost 3 quarts for the Dana 60.

Ford does not use gaskets for the diff covers. They use
Permatex® Ultra Black® Maximum Oil Resistance RTV Silicone Gasket Maker
However, gaskets are available at some auto parts stores if you don't like that new-fangled RTV stuff.

[lariat 7.3]

ok thanks. so do u have to pull the diff covers to drain them?

[txfxl]

yes you have to pull both to get the fluid out