Best Rear Diff Ugrade?

[zooterboy]

I have a 2003 7.3L 4x4, and it always spins one wheel.. I have a steep uphill curve by my house I go up everyday and no matter what It always spins one wheel, I have tried to tap the brake pedal to get it to lock the rear diff and 2 out of 20 times it will work.. Its just really hard to get it to lock. Is there any addatives I can use to make it work better to it is time to upgrade?

[Stroken7.3]

Detroit Tru Trac.

[thecaptin]

100%

[Dietoremain]

thats odd, my LSD hooks up right away no problem. Maybe you need new fluid?

[Stroken7.3]

Doesn't sound like he's got a LSD.

[Dietoremain]

ha then his cheapest upgrade would be to find a wrecked truck with one.

[CT Performance, Inc.]

Best..ARB, there when you need it and not there when you don't

[85_305]

The problem with these Ford rears is they tend to wear out (the lsd). Tapping your brake pedal does NOT engage the lsd in these.. spinning the tires faster does. They are a mechanical LSD.

First of all, consult this chart to see which diff you have:
What is my Ford rear end ratio, do I have positraction - Drivetrain.com

So there is this stuff from GM.. a friction modifier.. that should restore the LSD function. You should flush the old fluid out and replace it with GM friction modifier or any list of other friction-modifier additives.

[CSIPSD]

Truetrac...

[Shadowfax]

tru tracs are for pussies.

just get a full detroit locker. I ran a arb in front and detroit in the rear on my bronco and loved it on and off road. dd'ed fine and was awesome off road.