Knowing the type of front axel in order to decided to add limited slip fluid - Hi everyone I have Seirra 1500 4x4WD 20111 and I was advised not to ...

Hi everyone
I have Seirra 1500 4x4WD 20111 and I was advised not to use a limited slip additive for the rear diff becuse it has diff lock. I am wondering if this is true for the front axel. Ie. Should I use limited slip additive or it isn't required or recommended?

In the user manual, they have put two recommendations for the type of fluid for the front axelI and this confused me. I am attaching an image with red underline of the two recommendations.

I will appreciate your help in clarifying the confusion.

Nawwaf

It's an open diff so no friction modifier is necessary and just use a synthetic 75w90, it's what you should use for the rear and it's just easier to have the same fluids.

Open diff.

75-90 is all you need.

GM recommends 80w90 dino in the 1500 and 75W90 SYN. in the 1500HD 2599HD and 3500HD trucks. No additives in either end.

@jitbixler, @badmunky, & @wildchevy

Thank you for your replies.

@wildchecy, could you please explaine what is Dino vs. SYN

dino is a lube made from crude oil witch came from dinosaur stuff 50 billion years ago and syn is synthetic.