what rear diff fluid

[2001 greenGT]

my 2001 mustang gt is leaking rear diff fluid and i dont know what fluid to use please help

 

[BurningRubber]

If I remember correctly, I used 75w130 or something similar.

You need a friction modifier to add in (some fluids come with it, it will be labeled on bottle) for your limited slip differential.

I'd go fully synthetic.

 

[Kilgore Trout]

2001 is the year they switched IIRC. You either need 80-90 standard gear oil or you need 75-140 synth. Either way you will need the friction modifier. Go to the parts counter they will sell you exactly what you need.

 

[bhuff30]

It may be important to figure out what is leaking and why as well. I had a leak at the front seal because it had a bad pinion bearing. It ended up costing me a lot more money because I didn't take the time to figure out WHY it was leaking.