It's 4 wheel drive, 5.4L V8, 4 door, white and awesome, lol. But how do I find out if I have an LSD? How do I find out if it locks in 4HI or 4LO? I tried going to Ford and they weren't very helpful. Can anyone help me out???

 

For gears, look at the tag on the drivers door under axle. Get that code and check the code list.

 

Get the axle code off of the drivers door sticker. It should be a two digit code, like a letter and a number or two numbers. Come back and post the code and someone can tell you what you've got.

 

Your next question will be where do you find the list. You run a search, but here it is.

F-150:
19 – 3.55 Non-LS
18 – 3.08 Non-LS
H9 – 3.55 LS
B6 – 3.73 LS

 

The other way to tell if you have LS is to block the front wheels, jack up the rear end, put the truck in neutral and spin one tire. If they both turn the same way, you have LS. If they spin in opposite directions, you have an open differential.

 

And while you are at it, mark a tire with a spot on the ground and mark the driveshaft. Turn the tire one full rotation and count the turns on the driveshaft. That will tell you the ratio.

 

Pretty sure if its a 4x4 and XLT.

Your LS w/3.73's

 

not necessarily....i have 3:55 LS

 

Thnk you guys for the help. It really helped, a lot! The axle code says B6, which looks like 3.73 gears with limited slip. I owned a 2WD Tacoma before this truck and didn't know much about 4WD, I just figured it would help me get through dirt and snow better. Now when does my LS engage? Does it do it in all drive modes (2HI, 4HI, 4LO) or just in certain 4WD modes? Since it's limited slip, will the diff lock in 4HI or 4LO? Believe it or not but you guys are much more help than Ford, lol.

 

It's a simple limited slip, its engaged all the time, 2 hi, 4 hi, 4 lo. And no it will not lock, its not a locker, it's only limited slip.

 

I guess I take it LS is just as good as a locker. And do I take it only the rear diff is LS and not the front?

 

Yes only the rear is LS, the front is an open diff