Differential Fluid

[Lemonth]

Hey guys, I was wondering what you recommend to use in the differential of a 2014 GT with stock 3.31 non-Torsen. I'm going to be opening it up to change the cover. I tried searching a bit for this, but couldn't find any definite answers. So far I'm looking at 3 quarts of Redline Heavy ShockProof with 4 oz Ford XL-3 Friction Modifier. Would you guys recommend this or is there another fluid that would better suit.

 

[oldmodman]

Redline is an excellent lubricant. So is Amsoil. As long as you follow the manufacturers requirements as to amount and type of oil you will be fine.
Just be sure that the oil you decide on doesn't already have the friction modifier in it as it comes out of the bottle. Too much modifier can foul up the ability of the clutch plates (if any) to lock up at all.

 

[SID297]

I've been running Royal Purple, but I would not hesitate to use Amsoil or Redline.

 

[UnleashedBeast]

Assuming you still have the stock gears/rear in your car, this is what I would use.

Amsoil Severe Gear 75W-140
and

Amsoil Slip Lock friction modifier

If your gears whine, I would recommend Red Line Heavy Shockproof, but never use Red Line's friction modifier. That stuff isn't great. Use Ford's friction modifier with Red Line. However, if your rear end is currently silent, go Amsoil.