Does anybody know how the "Limited Slip" works on the Superduties? I have a '93 f150 wiyh traction lock, and I know it works on a clutch system that does slip if you are really stuck - when you need it most. Have they improved this on the Superduties? Is it the same basic design?

 

>Does anybody know how the "Limited Slip"
>works on the Superduties? I
>have a '93 f150 wiyh traction
>lock, and I know it works
>on a clutch system that does
>slip if you are really stuck
>- when you need it most.
> Have they improved this on
>the Superduties? Is it the same
>basic design?

Good question, how does your truck perform on ice? I have the same truck with the ls and it really kind of sucks on ice!










Evan A.K.A. PastMaster
1993 F-150 302/E40d XLT
1989 F-150 302/Aod 4x4 XLT Lariat

 

My '93 f150 2x4 with traction lock works great climbing hills in the snow etc as long as you have one wheel in the traction, but if both tires lose traction - look out - the back end will always slide down hill, even with chains! Traction lock has its pros and cons. I would rather have it then not on my 2x, but not sure on a 4x. The traction lock on my '93 I think is out dated in design, that is why I was hoping they have improved it on the new SDs.

One thing I know about my '93 traction lock is that it reduced my mileage because I had the dealer add it after purchase, and it was noticable. I think it uses up tires faster too.

The best system to have would be one that slips freely to a point, then locks solid. The technology it there already in the abs, but it must be a cost factor in applying it to the differential.

 

1st of all how can you expect to get any kind of traction on ice? lousy straight line traction on ice has nothing to do with LS differentials. good tires and weight will help more than anything. And not fat mudders either, the skinnier the better(more psi in contact with the pavement) If you are talking about the truck sliding sideways on ice during straight line accel, then your only other option would be an open diff and you would do nothing but spin one tire. Even more useless. The only downfall of a tight LS diff or a locker on ice would be in tight turns(may cause sliding). As for ABS, it has nothing to do with the diff, it just compensates for a heavy foot(yes, a heavy foot) by applying the brakes or dropping cylinders (both rear brakes at the same time on most trucks including the SD). If you want to turn the LS off you gotta get air lockers. Even a 4x4 is near useless off road without at least a rear LS.

 

Back to the original question, is the ls on the sd a simple clutch system like on my '93 F150, or have they improved on it?

I agree, ls is better then no ls, but there are disadvantages to conventional ls too.

Since the 373's are hard to get with a standard transmission, has anybody explored adding ls to at least the rear differential?

I stand by my theory of applying the abs technology to ls. Think about it - the differential would be "open" until a sensor indicated it was slipping more then a pre-set amount, then the clutch would kick in and lock it, even to varying degrees. This is similar to abs technology, only applied differently. Yeah, I'm no expert, only an experimenter who likes to theorize -- It's an American tradition!

Curly- You peaked my interest about the "Air lockers", explain these to me.

Dean

 

I've never seen one work in person but it is a locking differential that you can turn on and off using air pressure from an on-board compressor/reservoir. OFF=open diff ON=locked diff
Start a new thread with that same question and I'm sure someone with more info will fill you in. I understand they're about twice the cost of a detroit, but the cats-a$$ on the trail.

 

There are three types of rear ends, open diff, limited slip, and lockers. You can not get a locker as a factory option in a Ford truck. All three have their pros and cons. Well actually, I can't think of a "pro" for an open diff but I'm sure someone might be able to come up with one. The con is if a wheel starts spinning, you can forget about it, you're stuck.
The limited slip is a step above an open diff but, it is still as the name implies, "limited." Limited slips have either clutch packs or some have cones. If a wheel starts spinning it will supply a percent of the torque to the none spinning wheel. If you aren't stuck too bad it will get you moving but, if one wheel is off the ground you can pretty much forget about it. The clutch packs also after time wear out and become useless.
Lockers are the best of the three when it comes to traction but aren't very practical for most people. If you plan on going out and playing in the mud and rock crawling all the time they're great because you aren't stuck unless you have both wheels spinning. They are also the worst on ice and for just driving around town. They eat up tires and are noisey. Most manufactors don't offer lockers because most of the general public would not like them and would never need one.
What you are describing with the abs is already offered on many cars, they call it "traction control." There are sensors on the drive wheels and if it senses a wheel spinning, a computer will activate the brakes on the spinning wheel so the diff will think if has traction and apply power to the other wheel. On some of the more advanced systems the computer will also control the throttle and so on. They may offer that system on some of the luxery SUVs but, I don't think it is offered on any pickups.

 

There are several options within the realm of limited slip. Many of the serious off road folks like the differentials made my Torsen. They use a different system of gears that avoids clutches and the like. A "locking" differential is just not practical for almost any application except if you want to move in a straight line. My 4x4 tractor has a foot pedal that locks the rear differential and it will skid the front wheels if you try to turn the tractor with the rear differential locked. This is not such a big deal on dirt but really bad on pavement!