I am headed out on a cross country trip in 3 Days and wants to change the fluids in my diffs.

1. What are the capacities of the front/rear diff?

2. What Brand Gear oil do you guys prefer?

Thanks.

Its a 2003 Explorer 4.0L XLT

 

i think i bought 3 quarts for each and used over 2 on eahc. the rear should be 75 w 140 full synthetic. the front can be the older 80- 90 gear lube... but i bought 5 quarts of the new and split it between the front and rear.... you inow the rear does not ahve a cover anymore ?.. there is a big 1 inch (about) drain and a 1/2 inch fill.. no cover to remove.

 

Thanks for the reply. I took a walk into the service bay at the Ford dealer here and quizzed the mechanics. Funny most of them didn't have a clue. One of them said he was sure it was 2.5 like you said. Tried telling me I should have it done there, said it was pretty tricky...haha.

 

So is this a 2002 like the thread title states or a 2003 like you typed at the bottom and is in your sig? I don't have the service manual for the 2003, but do for the 2002. They are probably the same.

As mentioned by Steve above, the rear differential takes 75W140 and the manual specifically mentions synthetic. It also requires a friction modifier additive (EST-M2C118-A). The capacity is 1.23-1.37 liters (2.6-2.9 pints) for the gear oil and 4 oz of friction modifier. With the vehicle level, the fluid level should be 1/4 inch below the bottom of the fill hole.

For the front differential the factory service manual suggests 80W90 gear oil with a capacity of 1.54 L (3.25 pints). This should bring the fluid level to 0.38 in below the bottom of the fill plug.

Since I'd hate to think you're changing the differential fluid without also changing the transfer case oil, I'll list that information too. The transfer case requires 1.42 Liters (3.0 Pints) of Mercon ATF.

The 2004 service manual suggests the same capacities for the transfer case and front differential, but calls out 1.65 L (3.5 pints) of 75W140 and 0.12 L (0.25 pints) of friction modifier.

Either way, having 2 quarts ready for each differential should be plenty unless you have a tendency to spill a lot.

-Rod