Hi everyone I am looking to do a fluid change in my 05 250, I am wondering what fluid all of you guys are running in your diffs? Thanks everyone

 

I use Valvoline Full Synthetic 75w140. It's formulated for limited slip differentials so no additives are needed.
https://www.napaonline.com/napa/en/p/VAD982/VAD982

Mobil Synthetic is also popular.

 

I use royal Purple 75W-140 synthetic gear oil and AR-9100. RP is a little more expensive then other synthetics and it is available at Advance Auto. I also have a larger diff cover that increases my capacity from 3 to 6 quarts.


Ed

 

I also use Valvoline Full Synthetic 75w140. Great price too.
although I think I did add slip modifier when I changed mine.

 

I'm using this, seems to work OK:

Castrol MTX Full Synth 75W-140

 

Fleet Farm 80w-90 but that's because of my true trac

 

Lucas synthetic 75w140. Hytec diff cover.

 

Thanks for the input everyone!