I just installed a benchmark designs oil pan and threw in some mobil 1 5w20. But I'm having a hard time locating the mobil 1 diff fluid. Even my local Walmart Supercenter that suppose to sell everything from food to car tires don't stock it!

 

I personally would go with a synthetic. As for the brand it's going to be up to you. As you can see everyone has their favorites for their own reasons.

I run Amsoil 75w90. I change out my rear fluid more frequently do to it's 24/7 use vs. the fronts occasional.

 

I like synthetics. I run Amsoil 75w90 in the front and Amsoil 75w140 in the rear. I did not need an additional additive for the limited slip with the Amsoil.

 

why do you run two different weights?!?

 

I'll hazzard two guesses:

1. He tows a trailer and the extended viscosity range is per the owners manual.

2. Some people just do since the rear differential is always seeing torque. If you don't tow it doesn't hurt. Don't know if it helps. I have read there may be a slight mpg penalty.

Just my

 

Mine's now a year old (7.5K miles) and I'll being doing them in the next week or so. Mobil 1 is going in.

 

I just changed out my fluids with Mobil1 75w90. This is the first time I have ever messed with diffs, my first jeep. When I went to fill the front (d30) it only took about 9/10 of a quart. The rear (d44) only took about 2 quarts. I filled them until they started running out of the fill hole. Should I open them back up and see if they will take more?