Hey guys so I just wanted to make sure that I had this right, but it takes 1.8 quarts each, to fill both the front and rear differentials right?

I decided to go with 75-140 mobil 1 synthetic. That should be good right?

I just changed the front differential and I kept filling until it was spilling out of the fill plug.

Also do I need to add friction modifiers?

 

Yes, go to the 75 or 85W/140 for better wear protection either as a synthetic
or Dino juice.

 

So that's a yes to the friction modifiers Mike?

 

Nope on the modifiers. Make sure to use the same fluid in your t/case also.

 

Hm...well I recently changed the t-case and filled with regular 85-140. Is that big deal if I run that and the diff's have 75-140 synthetic?

 

No, that is fine.

 

When I changed the diff fluid, I used the BG synthetic (BG rep wrote off fluids for transfer case and both diffs on my vehicle for "sales research"). The diff kits came with the limited slip additive, and he said to use it, even though I have open diffs. He said something to the effect of limiting noise and foam. This is coming from a BG rep talking about BG products. I cannot say the same would hold true with other brands.

 

The modifiers are for limited slip differentials.