I Was at the track last nite. I am running hoosier slicks. When i do my burnout and let of of the throttle, one of my tires is grabbibg traction about the half way through the box and the other is continuing to spin. I don't think this is normal. My friends dosen't do that. When i launch off the line it feels like only one tire is spinning and dosen't grip till i have completly launched the truck. It dosen't spin bad, but i can tell it my self. The best 60 foot i can pull is 1.97 with slicks. and multiple mods (in sig). I have a friend with a 99 that pulled a 1.74 on slicks (the same slicks i bought them) with less mods. Is there somethin wrong with my diff. If so what do i need to do. I am going to change the fluid this weekend and add some friction modifier. Thanks

 

I'm not sure about the differential (I'll leave that for the pro's)

The traction probem can be controlled with tire pressure.
Which ever tire is not spinning is getting traction, the other tire isn't.
the tire that isn't getting traction, lower the pressure.

My truck wasn't launching straight, It was pulling to the left, so I lowered the pressure in the right tire and it straightened out.
The Left tire was getting traction and pulling me to the left, so by lowering the pressure in the right, it evened out.

Now....
back to the differential question:

youc an always change the fluid.
and see what condition it is in.

go to Ford and buy the oil with 2-3 activators.
change the fluid, look for metal flakes, very discolored fluid etc...
There is NO gasket, just need some gasket in a tube goop

 

not being to smart with differentials, im not sure if im right on this, but it sounds like the clutches that make your differential a limited slip are no longer working. If thats the case, a fluid change might not even do anything. Since its 45 bucks or so for fuild i would hold it off until you figure out whats up, you might need a rebuild.

 

Thanks