Last night I was backing up with my gooseneck trailer when the right rear wheel started spinning in the mud. The left rear wheel was on pavement and wasn't spinning. I'm supposed to have the "Anti-Spin Differential Axle".

Does the "anti-spin" work in reverse?

Enquiring minds want to know.....

It makes me wonder if they gave me the "anti-spin" axle.

 

Read the owners manual...it will explain how it works. If you are at a dead stop, some brake modulation is required tol get it to enagage.

 

Found this on another Diesel site, and thought it would be of interest to all 3rd Gen Owners with LSD's




The following is a S.T.A.R. Center Case Report:
Report created Jan 6 2004
Updated Jan 13 2004

Customer says his trac-rite rear diff is not working?
GCK1: 01/06/2004
Recommendation/Solution
Review AAM Trac-rite diff characteristics. Rear diff is working or truck wouldn't move. It will overrun like standard diff if operating on extreme differernces in surfaces. (Ice under one rear tire with other tire on dry pavement.) No further action.
:GCKI:01/06/2004
The 2003 heavey-duty Ram uses and American Axle helical differential or Trac-Rite. The Trac_Rite differential is different then Trac-Lok in that it uses helical gears (Trac-Lok uses clutches) to transfer power to the opposite wheel when slippage occurs. The transfer of power from wheel to wheel is torque sensitive and must have both wheels spinning (not stationary) to function. It is possible for the Trac-Rite differential to not send power to a wheel if is not spinning. Example: Accelerating from as stop and one wheel is on ice and the other on dry pavement. If accelerating to fast, the wheel on the ice may spin and never send power to the whell on the pavement side. A slower start may be necessary to start the vehicles momentum.
A written test procedure for Trac-Rite is not listed in the repair manual and the following points should be noted:
Testing the Trac-Rite differential while the vehicle is lifted and turning one wheel by hand, the opposite wheel will turn in the opposite direction. This is normal.
If the Trac-Rite assembly has and internal failure it will lock axles 100% side to side.
To test the Trac-Rite process, raise vehicle on appropriate lift, place into gear and accelerate quickly (hard launch). A second technician will witness both wheels turning at the same speed at the start of the acceleration.
Another test for Trac-Rite is to slowly drive vehicle in an open area and completely turn wheels to one direction and accelerate hard.. The vehicle will experience tire hop or shudder. This is normal. Trac-Rite differentials do not require friction modifier and should be used only with SAE75W-90 GL-5 synthetic fluid PN 05102232AA.
The Trac-Rite differential found in the American Axles may look like the helical gears have ground away the case. Six small half circles are noticable on the side of the differential opposite of the ring gear. These openings are desinged for oil flow and are not the result of the helical gears grinding through the differential. Please do not replace the differential case or any other part of the axle due to these openings.
Note: All American Axles require Mopar lube part# 05102232AA synthetic and does not use a friction modifier.
RAB40: 01/13/2004






Looks like both rear wheels must be rotating for it to operate properly , so not much help starting out on a slippery surface in 2WD.

Nothing like the old positraction with clutches the way I read it.

 

Let the wheels come to a complete stop. Apply brake pressure, then add throttle.

 

Thanks for the brake burn directions monkey

 

There is one benifit, you don't have to worry about it wearing out after a few thousand miles since there are no clutches.........

It would be sweet to have the powerwagon set-up. At least in the rear.

 

our 03's with the AAM's should be called "limited slip" cause are certainly limited!
and on the same token the old Dana units should be called "Anti-Spin". i like the idea behind the AAM system, but for plowing snow where you stop and restart, it is POOR.

 

Mine is not a anti slip.Does anybody know of a after market kit for these rear ends?

 

I'm not sure. You could check in the back of a 4WD mag and make some calls.

I do know AAM does make an automatic locker that GM uses in their 2500 and 3500 HD trucks (G80 Option). It's been known as many things, but it's now called the TracRite LK. It works as a locker from 0 to 20 mph, then a flyweight turns it into a ltd slip or open diff, can't quite remember, past 20mph (for driveablity). I had one on a 2002 2500HD, and it locked up both axles really good, no delay at all.

I'm sure you could get one through a drive line outfit and have it installed since we have, for the most part, the same 11.5". Although my GM had the AAM10.5" (or 14 bolt) rear, I'm pretty sure AAM makes for the 11.5". If you get a 2500HD or 3500HD Duramax with the G80, I'm certain you get the TrakRite LK. I wish DCX used these instead of the TracRite GT for our rigs. I'm sure your looking at about $800 bill, which would be pretty reasonable.

 

Seems crazy but I'll try it next time. Thanks guys.

 

thanks for the info Monkeylips

 

It will not work in reverse. The differential is a helical design, that works by use of gears. Those gears are cut to apply forces in one direction (forward). They tend not to work well in reverse.

There are pro's and con's to differential designs. Helical diffs are much smoother and don't bind or drag. They can be made to have a huge bias ratio (like the race Torsen unit I run in my Camaro) if they want, but there are downsides to doing that to a truck, primarily that it can make for a lot of power oversteer in slippery conditions. The low bias cut of the gears in our diffs is why the don't tolerate hugely different wheel RPM. But if you think about it, when you need an LSD, it's slippery, and one normally doesn't want a lot of RPM anyway.

Clutched or Coned LSD's have parts that wear out, and are not as long lasting. Lockers are either open or locked and the change-over is not exactly smooth. That can kick the rear loose. I've seen folks slide into trees with the bed when their lockers banged in.

Helicals are not good for rock-crawling since they just go open if you unload (dangle) a wheel. They are good for mud (forward) because the wheelspeed variance between sides is not huge (since you are in mud).

Lockers are good for rock crawling since you can have a lot of RPM difference between wheels, and you don't want the diff to go open with a wheel in air. And if you use a standard clutched LSD the wheelspin eats the clutches (much like the real clutch would get torn up if you were spinning the engine a lot faster than the tranny input shaft, otherwise knows are slipping the clutch.

"Normal" LSD's with clutches or cones are a compromise. They never fully disengage, which means you can get some hopping in tight turns (which is why they use friction modifier to help the clutches slip a bit, and that lessens the problem). They can't trasmit as much power to the other wheel as a locker or a big bias ratio helical design.

FWIW, I hated GM diffs for my use, and much prefer the helical types. I've been stuck with my 2500HD and it's GM diff in places that I've never had a problem with in the Dodge. YMMV......

 

I wish I could just get detroit lockers for the front and rear

 

I did check with my largest differential supplier. They carry a LOT of product from ARB, Detroit/Truetrac, Auburn, Zexel/Torsen, Eaton and others. NOTHING available for the AAM axle at this time.

But I'll keep an ear to the ground and let you know if I hear anything.

 

As has been mentioned previously, the PowerWagon ? has a selectable lockers front (9.25in) and rear (10.5in), so there should be parts for the front at least.