I become confused with the limited slip and non-limited slip rear differential differences. My 2006 F-150 had the 3.73 limited slip rear end. I know that this allows the rear wheels to turn at different speeds when making a turn. I'm also familiar with the noise/chatter associated therewith.

I'm now looking at a 2008 Expedition XLT 4x4 equipped with the 536 HD towing option. I believe the towing package also provides a 3.73 rear end (axle code 16) but I think it's non-limited slip. I will be towing a 27' TT. I also live in north central NY state so this thing will see snow.

I read somewhere that having a non-limited slip rear end means I'd have a 2WD vehicle. Only 1 front wheel and 1 rear wheel will drive the vehicle. What do I gain/lose with a non-limited slip. Is this rear end also mean it's a "locker" axle?

 

Might want to read this thread.

https://www.f150online.com/forums/20...rear-axle.html

 

Thanks for that link - I didn't see that thread previously.

So in my '06 F-150 4x4 with LS 3.73, I only ever had 3 wheels pulling while in 4WD? One of the front wheels is NEVER driven? And if I don't get an LS in the 08 Expedition I'll have one front and one rear wheel working, even when on slippery surfaces?

 

depends how hard you mash the skinny pedal, when im in snow or mud, usually all 4 wheels spin lol

 

The 2008 Expedition probably has electronic traction control, which means if one rear wheel starts spinning it will brake that wheel so power can be applied to the other side. This may be true for all 4 wheels. I'm not sure exactly what they have, but they do have a complex traction control system. Of that I am sure, unless you have the cheapest optioned Expedition you can buy.

 

One thing to remember is when in 4x4, if you have LS, at least 2 other wheels will have to lose traction before all wheels will just be spinning or still, since both axles will spin at at the same speed. Without LS only one other needs to lose traction before this happens.

 

And a Traction Lok rear should not ever make any noise. If it makes noise when turning, the viscosity of the lube is not correct.

 

Limited Slip and a locker are two very different things and not one in the same.

And the post above mine is correct. Some lockers may click in turns, but the factory LS should never be heard.