Originally Posted by
boots6868
I forgot to mention. you dont need friction modifier if you dont have locker rear end. look at your tag on the rear. if it has an L in the ID tag..ie..
3L55, 3L75 then its a locker if it reads 3. 55 then its open rear and no need for modifier. be careful with your modifier too much and you will render your locker useless, too little and she will lockup on corners. I usually add like 4-6 ounces then drive it if she binds up then add another ounce, till she drives nice.
I have the original window sticker and it says that I have the 3.73 gears. Does that mean it's a locker? I have not looked at the tag, it's dark outside.
Now, is it true that Ford recommends changing the diff oil to a heavier grade, or is it just a rumor? If true, what grade should I get? Shorod, above, said it says SAE 75W-140 in the updated 2008 manual. Is that the heavier grade?
Thanks.
PS - I still haven't figured out how to get the new oil into the diff with the independent rear suspension. The arm is right in front of the fill hole and it's a pretty tight fit. I'm thinking of pumping it in there but I might not even be able to get the hose in, it's so close that the hose might pinch when at that angle. I'll look closer tomorrow.