rear dif fluid?

[rebelyelltex]

so im just changing all the liquids i can since the rig has 110k miles on it and now im at the axles. what type of dif fluid do i use? i found nothing in the manuals, no books at the store, or anything. does it matter if its synthetic? what grade would y'all recommend? specs of rig below

 

[Yardape]

I use Royal purple 75w90.

 

[Justshootme84]

You need to find out if the rear axle has a limited slip or not. You'll need a gear oil with a "friction modifier" designated for the L/S if you have it. Regular or synthetic gear oil will burn up the clutches in the L/S otherwise. JSM84

 

[Yardape]

Royal Purple has the friction modifiers built in >-

 

[rebelyelltex]

yeah ive got ls. ok thanks alot! i almost made a big mistake with that one, so glad i asked on here first.