ok so i always spin my tires everywhere and from what i've noticed only 1 wheel spins. but tonite i spin them in my dads garage :lol: and when i got out found 2 large black footprints so i was at a loss.and i have read in my owners manuel about how limited slip was offered but i was wondering if theres a sure way to tell i would say that tonite proved it but both tires never spun anytime before until now any help is welcomed.

Put a floor jack under your diff. & jack the rear wheels off the ground. Turn one wheel, if they both spin in the same direction you have posi. If the other wheel spins in the oppisite direction but not at all, then I don't.

Open faced differentials will lock up both tires on a level flat surface, like a race track or a drivway/garage. If the truck is where more weight is on one tire than the other or the truck is rounding a corner or on uneven ground or you are in gravel / mud then that is when the spiders let go and one wheel spins. Generally its the wheel that has the least amount of friction or traction. That is when an open faced differential really sukkx.

Limited slip or what everyone calls Positrack (Limited Slip) will also spin only one tire in many different cercumstances. A corner is one example also if the clutches are burnt or worn out.

CHances are you have the most common type differential which is void of any special posi unit.

To tell for sure, remove the rear cover on your differential. If it is limited slip it will have springs & clutches in it. A regular open face only has 4 gears there.