Im pretty sure limited slip is not standard on the FX4 unless they changed that sense 2004 it was an option I had to pick. if one wheel was spinning and the other was not. that should indicate the linited slip was not working properly or the limited slip was not strong enough to push your truck with the one wheel that was still on the ground. it was probably slipping. or you dont have limited slip. if it was slipping I would ask your dealer about why.

 

Josiah.....Ford does has limited slip in the rear and in the front, unlike chevy or dodge. The way Chevy's positrac works, does not allow them to put positrac in the front, because on an icy or slippery road it would pull the truck towards the ditch. Ford on the other hand will not. The reason is because Chevy designed there positrac system to divide the power evenly(each tire receiving 50%). The transfer case as you know will divede the power evenly b/t the front and rear differential. If chevy put positraction in the front differential (so that both tires could pull), then the truck would have major problems driving straight on a slippery road. Ford splits the power that each tire can get. On either differential (front and rear), one tire receives 70% and the other gets 30% of the power supplied through the transfer case. Therefore the truck can transfer power to the tire that needs it, making it capable of driving straight on slippery surfaces.

 

Show me any print backup of your claim that Ford has LS front & rear in the F150 (not talking the HD fulltime). You can't because it doesn't exist.

 

your saying there is a L/S in the front??
the rear one sucks, its too loose. cant you shim the clutch pak and make it stronger? I thought I saw that trick on some mustangs. even in the rain sometimes I get one wheel around corners. pisses me off when I want to do a monster drift into the side of a honda.

I've had several l/s diffs, some work alot better than others.

 

Dexter, with your extensive knowledge of Ford and differentials you should already know this. Do you have any experience working on differentials, if so i would like to hear about it. Why are you under the impression they do not. Do you also disagree that the superduties have limited slip in the front as well? I do not have a "printout" to prove my point. If you want to test it, either get stuck in a deep mud hole and watch all four tires spin, or put the truck on jack stands and see for yourself. One more reason you SHOULD be able to tell is when 4x4 is engaged and you turn on concrete. Have you ever noticed the tires chirpin. That is because both tires are pulling. Trucks without limited slip do not do that.

 

. . there is no LS in the front differential.

 

Tire chirping in 4WD is because there is no center differential on the F-150, so the tires chirp when the front and back are locked together in 4WD but moving at different speed through a turn. I've looked at the F-150 specs at the Ford Fleet Body Builder's site. The front diff is an open diff - no limited slip.

Any truck with no center diff will chirp tires in a turn, even with open diffs at both ends. That's why the Ford system is PART-TIME 4WD, and you shouldn't be using it on concrete . . . . .

The window sticker for my '04 FX4 shows the limited slip rear axle at no charge, so it was part of the FX4 package, but there is no mention of a front LS axle - and there would have been if there was one. Ford doesn't offer it - probably too big a risk of someone running off the road when the LS kicked in on a turn and the front end started sliding.

 

I still don't get why all 4 tires dug holes when I got stuck. On my 99' 4WD Lariat, I got that thing stuck in 4WD and it dug holes with the front left and back right tires. That truck has an open rear 3.73. You are telling me I don't have limited slip up front??? How is that possible? I guess I am confused.

 

The tire with the least traction up front will spin. If that tire digs itself down, then it has more contact with the ground. Once it has better traction than the other tire has, then it will stop spinning and the other one will start to spin. This is especially true if you let off the gas or if you try to rock the truck, since the traction is constantly changing. They usually aren't both spinning at the same time, but they will both spin, but just take turns spinning (if that makes sense).

If you have an LS rear and open front diff then you really have a three-wheel drive truck, but the conditions determine which front wheel it's going to use.

 

there is no slip in the front end. this is why the tires chirp if turning in 4wd. the tire on the outside or the turn is trying to turn faster than the tire on the inside of the turn but this is impossible because they are tied to the same gear with no cluch to give. so something has to give either you break a drive axle or the tires cherp. this is why you are not supposed to drive on dry pavement with 4wd. this is also why man invented the slipping rear end for the same reasons. the limited slip just means there is a cluch in the differential that allows one to slip but it dose not slip so easly it has friction against a cluch that keeps both wheels driven unless enough torque is against one to cause the cluch to slip. hope this clears it up for you.

 

There is NO LS in the front differential, or else you'd know about it. Plus, these trucks would perform a worlds better offroad with a LS up front. The rear LS is optional and is weak at best, it could use some work.

I wish Ford would offer an optional electronic/air locker.

 

I had a Bronco with LS in the front and a Detroit locker in the rear. If the additives were not just right, and on smooth sand or mud, the truck would start to "crab" or walk sideways and I would have to put it back in 2wd to get it to straighten out. But in the rocks and rough stuff, it was great. Mine was not stock. I can see why Ford would not put any type of locker in the front due to the weird handling it can give you under certain conditions. I never drove on ice, I can imagine it would get pretty scary.

Like Thumper said, the best way would be to have an air locker so you can engage when off road in the really rough stuff.

 

This is a good read, explains the differences in a ls and a locking.......

http://auto.howstuffworks.com/differential.htm