This may be a stupid question, but what exactly does a anti-spin differential do? Does it just keep the rear tires from spinning?

 

Anti-spin is a term sometimes associated with an auto-locking differential, like a Detroit Locker or Lock Right. It can also be used referring to a clutch-type limited-slip differential, or just about any other type of traction differential too, so the term is kind of vague as far as what to expect of a differential being called anti-spin.

Basically, a traction differential attempts to provide equal torque to both sides of the axle, and thus equal traction to both tires. Different differential designs are better at accomplishing this task than others.

An auto-locker uses ratcheting gear teeth to lock both sides of the axle together and allows the outside wheel to ratchet ahead and spin faster than the inside one during turning. Both wheels are under power at all times, just one is allowed to go faster.

A clutch-type limited slip has friction clutches between the two sides that keep both sides of the axle turning the same speed untill torque differences between them overcome the holding power of the clutches and they slip. This allows the inside wheel to spin slower during turning, or the tire with the most traction to spin slower on unequal traction surfaces, such as one tire in sand and one on pavement. The clutches limit the tire slip.

There are other types of traction differentials, but those are the 2 most common ones.

In an open (non-traction) differential, the inside tire in a turn spins slower but has no power. On unequal traction surfaces, the tire with the least traction spins and gets all the power and the tire with the most traction doesn't get any power and just sits there, which causes the vehicle to get stuck.

To learn more about how the different kinds of traction differentials work, check out these two websites: www.reiderracing.com and www.ring-pinion.com.

[Quote: "what exactly does a anti-spin differential do? Does it just keep the rear tires from spinning?"]

To sum it up, Yes, that's what it does (or attempts to do) .

 

Well my uncle has a 2004 ram with a hemi, and when he goes to do a burnout, it kinda sounds like the tires skip. like a err-err-err-err.

oh yeah, it has a anti-skip differential.