Manuellabour247

If you don't ever use 4x4 or at least engage the 4x4, it won't matter what gear you put in the rear swap. But then you should have gotten a 2WD, or disconnect your front DS. Whatever gear you have now in your rear is what gear you need to be looking for in a "new" rear end to swap. @brap

To the OP, definately measure the driveshaft the way mentioned in the above post. I didn't on my old 73 when I changed to Chevy 3/4 ton springs. Ended up having the front of the DS drop in the ground and try to pole vault my rear end. Wasn't really a fun day. Measure 10 times if you have to so that you have the proper length of a new one.

A7X

If he gets the same gear ratio, he can use 4wd... if he gets a different gear ratio, he'll hafta change the front or not use 4wd as well as have to buy a tuner so he can reprogram his truck so his shift points, speedo, odometer etc, are all correct

What do you get when you take the venom out of a snake? A belt

What do you get when you take the front drive shaft out of a 4x4? Stuck

brap

Ill try to dig up the work order from the last time. I realize my vehicle gen differs from the op. I found the thread thru the search option and he was on target with info I was looking for as well. As far as matching ratios , what's the easiest way to identify? Considering ill probably be pulling the part myself , I doubt anyone will have info on what's in it

A7X

Door sticker, axle code... easy as that

A7X

Also read any tags on the axle itself (yours and the donor), usually bolted on with the diff cover bolts.... there's no telling if somebody swapped another one in to a truck before they junked it/sold it/traded it in...

Manuellabour247

That was kind of my point. If it's not matched to the front axle then it might as well be a 2WD. Had a buddy swap a different great into his rear end then one night locked it in 4WD. Not a good night, and definately expensive.

They used to put a tag with the axle ratio on the third member. I doubt they do that now, but it's a possibility. If you do swap a new axle in, remove the cover to look at the gears. Check the fluid for excess metal as well.

A7X

You can also, jack it up, Put it in neutral, mark the shaft, spin the tires by hand... count how many shaft turns to tire rotations...

If open diff (one wheel peel)
Jack up one side only, leave the other on the ground and rotate the tire twice while counting drive shaft revolutions...

If limited slip diff (posi)
Jack up both and turn the tires one full rotation...

If your shaft turns 3.55 or a hair more that 3.5 turns... your ratio is 3.55 and so on...

How do you tell which diff you have you ask?

Well right off the bat being an 07 you probably have an LS... so take both tires off the ground and spin one, do they spin the same direction? Yes? LS... is the other spinning the opposite way? Yes? Open diff...


These steps are if you don't trust the door sticker and see signs of a possible swap out...

A7X

For people reading that may have a Chevy or GM vehicle and some foreigns with a posi loc etc... this is a ford forum but anyway... you may need to give the wheel a jerk to engage locking mechanism... otherwise it could act like it's an open diff and the opposite wheel might spin the opposite way...

Fords have clutch packs that will already be engaged upon slight movement....

Figured I'd add that

jferg92

You've been on a roll lately

A7X

I only work part time in the winter haha... normally if I have any free time I'm fishing... there's no ice yet and the boat is winterized

So here I am