That sucks that you are having problems with the ls in your truck because mine is really tight. I have 31k miles on my truck and it chirps the inside tire in turns on asphalt. And when its lose in dirt they both light up at the same time and I can kick my rear end out and go into a slide.

 

So I changed my diff fluid, it was about $45 said and done for RP synth and the gasket. What is the top bolt for on our back diffs? It's right above an electrical connection (probably temp sensor for the diff). This bolt had a 3/8" head. I started pouring in that hole and the damn stuff wouldn't go in, I then found the right fill plug, hope I didn't damage anything. I had black fluid pouring out contaminated with bubbles of water. No friction modifier added I will have a story in the morning. Before it was sketchy on spinning both 37" Mud grapplers, I have high hopes its going to be spinning them both now.

 

I think this is the rear speed sensor for the ABS system.

 

I thought there was a tranny sensor for that. Anyways there are 2 holes, the top hole is just a 3/8" bolt, the bottom hole has what looks like an air sensor/temp sensor with wires at the end of the sensor that run to the front of the truck. I was hoping that second hole was a covered vent just in case you couldn't get the drain plug out, but I have my doubts.

 

Correct, it is the rear anti-lock brake system sensor.

 

I can see why your fluid was contaminated from your sig. Do these rear axles have a diff breather. We need to figure out how to extend them. I have mine extended on my 85 toyota and my fluid stays nice and clean.

 

Josiah, hows it working for you with no friction modifier?

 

Bad news. I am getting a little worse mileage and still get a peg leg burnout. Let it work in a little more, I've put about 100 miles on it since. Yes they do have a diff breather and its up pretty high.

 

I figured I would chime in here on the LS issue.

NOT in 4 wheel drive, obviously:

I've had a 2001 Ranger 4x4 with LS: Back right tire would always spin.

Ive' had a 2005 STX 4x4 with LS: Back right tire would always spin.

Now I have a 2006 FX4 with LS: Back right tire will always spin.

It never seems that the LS kicks in and locks the other wheel! I've always figured this was just the way it is, but now im questioning if i've had a run of bad luck. Im tired of always having to select 4wd when accelerating from a stop in winter conditions (not to mention the delay involved when you select it at a dead stop) I don't know if this is all trucks with LS, because as you can see all i've had is Fords.

Driving with on side of the truck on dry pavement and the other on snow and spinning away really pisses me off. Don't get me wrong here, I love my truck. I just wish I could use the 4wd less to save on gas. However already having 60+ inches this year kinda makes it tough to not use 4wd.

Sorry im thinking of this as it comes.......

I wondering if I put more weight in the bed if it would help in the LS locking both in? Ill let you guys know when I load up 1500 lbs for a move.

A little off the subject.....Alaska doesnt use road salt, but some kinda cinder/sand mix (which leaves a lot of ice until April).
Any other city/state do this???

P.S. im not a hater, so dont get mad.

 

Normally you need some traction on the worse wheel to get a LS to work. Try putting the emergency brake on slightly and it should make the LS work better.

Ford has been forced to get less aggressive with the factory LS. Constant complaints about "binding", "chirping", and "chattering" have caused them to reduce preload and increase LS additive. On race cars with factory LS we always left the additive out completely. Its job is to reduce the effectiveness of the clutches allowing the diff to slip more around corners.