i have a 04 f150 4x4 .the truck was wrecked.rear axle was replaced from a 05 model but the same ratio same specs.frame was checked to factory specs and alignment is deadon.driving straight up is no problem.now the problem is during turns.the rear tires lock a little and it vibrates the whole truck .but if i switch to 4x4 then the rear will lock completely and will drag.pls help!!!

 

Sounds like the replacement axle has either a tight limited slip diff, or some aftermarket locker. Did the shop that installed it open the diff cover to inspect it?

 

I Have Checked With Em And There Isnt Any Lockers Installed On It.
Another Ford Tech Said That The Traction Control Solenoid Might Be Bad.does These Trucks Have Those?then Another One Said That
A Tsb Is Out That Requires You To Install A Clutch Pack On The Rears.checked With Ford And It Costs A Grand.and I Am Not Sure That Will Solve This Problem.any Ideas?

 

So if they know there's not a locker in it, then they did open the rear diff. Did they replace the oil with the proper mix of LS additive?

Read this caption.

They probably didn't rebuild the LSD, so they wouldn't have soaked the clutches, but they should have used some additive.

 

It sounds like you may have two problems to me. First, it sounds like your LS is not working properly, or there is an incorrect amount (if any) of LS additive. The second problem sounds like a transfer case issue. Or possibly different gear ratios between the front and rear differentials. For instance, if the front has 3.55s and the rear has 3.73, when fwd is engaged the front tires will spin faster and possibly "drag" the rear tires. I would pull the rear diff cover and have a look for yourself.

 

nicely said
x 2

 

Thx Guys.i Will Get It Checked All Over Again And See If There Is Anything Else To It.