Hardrock,

Don't confuse Posi (GM's name for limited slip) with a true locker. You'd be more accurate to describe Ford's LS as "limited traction" rather than "limited slip". It breaks away (lets a tire spin) at a fairly low weight. It is definitely not the best LS unit in the world and is better suited to daily driving and towing, than it is to off-roading or abuse.

Basically look at it like this, LS units are a compromise. They are intended to offer the truck owner better traction than an open diff, but still not **** off the yuppies that don't want the noise of a true locker. They do okay, but they are a compromise between performance and quiet operation.

That is why I like the TruTrac, as an LS anyways. It is as close as you can get to a locker, without the noise and bad street manners.

More expensive, but offering the best of both is the selectables. I have the ARB's in mine and don't think I'll own a truck without one, at least one, ever again.

 

My '01 has only 22K miles on it - I've been through two sets of tires in the back already, because the traction-lok makes the inside tire spin a little bit on every sharp turn. Also, I do use the V10's power a bit, so both rear tires are lower on tread than the fronts pretty quick, but I'm not pealing out on right turns all the time.

Now, I'm not exactly easy on the truck but I certainly don't abuse it, but guess what? Because I make a lot more (and much sharper) right turns than left turns, and the traction-lok is somewhat doing it's job, the right rear tire is ALWAYS geting low on tread before the other side. I wind up switching sides just to even out the wear.

What I'm trying to say is, all that proves is the guy didn't rotate the tires a lot (like me).

My '01's traction-lok is pretty wimpy ... I can get both tires spinning if I go real easy power-braking and get them both going, but it almost certainly doesn't act like an LS on wet road or other low-traction surfaces. I can get a power slide out of it in a sweeping left turn, but other than that, almost useless without feathering the brakes.

I put an 8.8" Auburn HD LS in my '96 t-bird 4.6L, and it was a sled ...

 

I had a 87 Mustang with the 8.8 rear end and it had the Limited slip differential, and I have been comparing it to that unit. Because the previous owner , missabused this F250 truck I was just thinking the unit may be worn to the point that it is slipping a little to much.
If I had the money, I would buy a TruTrac unit, but right now I will have to stay with the Ford LS unit.
Thanks for the info.

 

All is not lost - try Fred's tip of changing out the gear fluid, and only putting in 2oz of friction-modifier, and keep putting in 2 more until it stops being noisy

Fred, please elaborate.

 

Replacing the clutch packs is a pretty easy job actually.I believe they come with the shims already.
Rich