Honda Hunter

It says my truck has anti-spin diff in the rear axle. Is it the same as limited slip?

braxton357

Yes. Probably pretty worn out by now too.

Honda Hunter

Ok thanks.

dozer12216

The FSM (factory service manual) gives a test procedure for evulation. Use two bottles of anti-spin diff lube when changing fluid.

bigfish95971

Anti-spin, limited slip, posi-traction, locking differential(not power lockers) all different names for the same thing. Some were trade marked is the reason for the different names.

braxton357

A locking differential is not the same as an LS in common terminology for what it's worth..
In the 70's ford did sometimes call their limited slips "locking diffs" though.

thenrie

The Power Wagon (the new ones) have true locking diffs, front and rear. Electric lockers. Having a locked diff is definitely not the same as limited-slip. Locked is just that - locked. Both wheels spin at the same rate. A low-budget trick rock crawlers use sometimes is to actually weld the diff up so that there is no slip, like a straight axle on a go-cart. That is what locked is. Limited slip allows...limited slip...between the right and left wheel, so that you don't break things or cause premature parts/tire wear while driving on hard surfaces. An open diff sends traction to one wheel...usually the one with the least traction. Don't go far off the road with one. You may have to walk home.

The varying terminology Dodge uses may be a product of which manufacturer made your axle (not stating that as fact...I really don't know). Somewhere back in the deep dark recesses of my mind, I seem to recall that Dana invented the term "limited-slip". Maybe they copyrighted it. My truck has an "Anti-slip" differential, according to the build sheet. I don't yet have the truck, so I don't know what axle is actually under it, but I expect it does the same thing as a "limited-slip". If you do the test outlined above (jack the rear axle up and manually rotate the tires) and both tires spin the same direction you have a LS. If they turn opposite directions, it is open.

Not to hijack the thread, but does anybody know what axles are under my truck (see signature)? Are both front and rear "anti-spin"?

bigfish95971

You are right Anti-spin, Anti-slip, Limited slip, trac-lock and all just names for clutch type limited slips. Power lockers like on the Powerwagon or Rubicon Jeep are true full lockers. All others are nearly always only found on the rear axle only. Hummer or the new FJ may have something in the front but I am not sure what. The only thing I know of that has any kind of limited slip in both the front and rear is the newer Grand Cherokees with Quadra-Drive II which had electronically controlled limited slip in both front and rear differentials and the transfer case. This is not traction control but in addition to it, and is the most sophisticated system I know of on the road.

If you have a new Dodge coming I believe they are from a company called American Axle. It may be a partnership of manufacturers. We dropped Dana a few years for bearing and reliability issues.

thenrie

I have a "new" Dodge coming, but it's only new to me. It's an 05 with 208K miles (see my signature). I pick it up tomorrow. I think it still the AA and not a Dana, though.

So, most front axles are open diffs unless an aftermarket locker is installed, correct?

totalloser

Front traction control is VERY VERY rare in OEM applications. The few out there are all lockers as far as I know-selectable lockers. Ratchet type lockers have been put in rear applications on some older vehicles, as well as "Gov locks" which technically were full locking diffs, but were IMO worse than a posi due to locking after a one legger already has you stuck.

Selectable lockers when locked the tires turn at the same rate, but ratchet type lockers, the wheels can travel faster than the carrier, but not slower. This means that if you send power to the axle, it WILL turn both tires unless something breaks. But the outside wheel in a turn can "walk" past the inside driven wheel to prevent wheel scrubbing. Example: Full case Detroit lockers, Lockrights.

Power locks, Track locks, anti-spin etc. are all clutch type positractions with the exception of the occasional gleisen torsen helical gear positraction in some more modern vehicles. Same design as "True trac" diffs. These are very smooth, require no special oil, and have no clutchpacks to wear out. There are several other positraction designs out there-like friction cone posis and a handful of other oddballs.