meangreenXLT

I am going to be changing my fluids soon and I know I need the friction modifier for my rear dif but will I need it for my front dif as well ? Thanks

05 super

No sir..just regular gear lube..80w90 i believe

meangreenXLT

Thanks I appreciate it. I think the manual says 75w-90

05 super

You're probably correct on that..i run 75w90 in the back of mine also..even tho it calls for 75w140..havent had a lick of trouble..i dont tow very often and dont have the high outside temps that some folks get.

darwinmorrow

Yes! Chilton calls for modifier in front and rear 90-140 rear, 85-140 front...

darwinmorrow

If you can afford it! Royal Purple has the modifiers already added. ..

05 super

I never noticed that in my Chilton..I think the owners manual says 75-90 for front and 75-140 for year..why would you need modifier in a front open diff?

darwinmorrow

I'm sorry! You are most definitely right about the weights! And I have no clue as to why modifier is needed. ...

tcp2

Friction modifier is for limited slip clutches in a differential. If it has no LS clutches, friction modifier is not required. Front differentials don't have clutches. Open rear diffs and e-locker rear diffs don't need it either, but it doesn't have any ill effects if you do add it in.

Chilton manuals are notoriously inaccurate.

BIGDAWG78

Royal purple 75-90 in front and 75-140 in rear.