Limited Slip Faceoff: Detroit TrueTrac vs. ARB Air Locker


Viking with a Hammer
thanks for your accounts guys, I think i will be going with the true trac in the rear. I too dont wan tot deal with clutch packs and such. nic ethe true trac is about 200$ cheaper than the locker. I assume the true trac feels simialr to an LSD where it doesnt snap lock up on you, so it will be a littl ebit more tame when bursting thru packs of snow on the freeway at 50 mph. If i do end up in a sitatiuon wher ei need to apply the brake sa bit, i can always set the parking brak eto drag a hair to give it tha tpreload.
Truck will fly through snowy roads with 2 Truetracs. When you run out of grip way offroad, get the chains out.

My trucks heavy and automatic, so a Detroit or Yukon locker in the rear is a no brainer.

Truetracs will be smoother and more predictable than an LSD on ice. You may get some front understeer from time to time. I just tap the brakes with my foot when a truetrac spins. Kinda like a weird heel and toe downshift. But more like toe and toe. Just adjust your pedals if needed.


New member
Just wanted to clarify with this one... I figure the poster has figured it out by now anyways, but you can't put a lunchbox in the front 8.8 ifs even though they make one for the 8.8 28 spline. Once the lunchbox is in there is no way to put the snaprings back on the axles to lock them in. Best bet is the truetrac up front... this is what I did.
Uh... thanks. Actually I hadn't figured anything out because I'm still stock in both differentials. No money for it yet. After all I am still making payments on the truck.
Also, having a warranty is nice. They just replaced my long block under warranty for an undiagnosed noise.
In all reality I'll probably not do anything until the payments and warranty are over. Just think it over and research. So thanks for the tip.
I always liked the idea of Truetracs.


New member
So we all know modern trucks have traction control. Ford and others have implemented something called Electronic Differential Lock. When I was in Colorado I felt it working, climbing some obstacles I'd get some wheel spin, then the truck would just climb up whatever obstacle I pointed it at.

So with the nice weather we've had, and thinking about differentials again from this post, I did a test last night.

Jacked up the truck and put one side of the rear axle on a jackstand, and the other side on the ground. Disabled the traction control and stability control. Made sure it was in 2WD, and put it in gear. Mostly level ground.

At idle nothing happened. The wheel in the air spun, and my truck went nowhere. At light throttle application I could hear the ABS starting to cycle, and the truck pulled forward slightly, but not enough to come off of the jackstand. If I let off the throttle, the ABS stopped cycling. The more I pressed the throttle, the more the ABS cycled, and the greater the torque transfer to the other side. It was controllable enough that I inched the truck forward until the jackstand was angled, but the truck hadn't fallen off. Then I put it in reverse, and inched back the other way.

It seemed to need quite alot of wheel speed difference before it actuated.

This is all with a completely open differential on a 2012 F150.
I may not ever need a newer differential. Snow driving would be more stable with a Truetrac, but I have no interest in anything with greater lockup than that.

Just something I thought was interesting and relevant, if you have a newer vehicle with EDL you probably can get away with not bothering with a differential change.


For mild stuff sure, looks like it will still let you spin the crap out of the spider gears though. Too much of that destroys them. Not too mention the one tire you have to roast off doing it.

My 93 has a new truetrac and it is very nice. Predictable and heavy duty.


For what it's worth, a TrueTrac in the front isn't as good an idea as it sounds. I ran one in the front of a previous 4Runner and it caused horrible understeer on slick or loose surfaces. I wouldn't put anything but a selectable in front, myself.

Sooper Camper

i drove a fullsize Bronco on un-siped 40" Swampers in the snow and ice plenty with Detroits front and wasn't nearly as bad as most people would have made you believe. They are predictable enough that you can manage, and IMO you really shouldn't be going that fast in those conditions anyway. 40+, you are just asking for problems regardless of what traction adder you have. especially if the road is twisty, hilly or mixed with shade/sun...slow down and enjoy scenery. IMO tire choice is more critical.

That being said, my truck is going to have a tightly shimmed Power Lock when I get around to it.


Supporting Sponsor - Differential & Axle Parts
Once you get used to having a mechanical locker in your rig it isn't a problem. With that being said, I prefer my ARB air locker in the rear over a mechanical locker.


Viking with a Hammer
And that doesn't cause problems in off-camber slippery conditions?
All of the slippery off cambers I've been on, it didn't matter. We ended up slipping all over the place. Going up hill crooked like a crab.

Detroit, ARB, open diffs. No difference, until the tire chains came out. I'm sure it happens with Jeeps and Hardcore trails, just doesn't seem to apply to fullsize as much.


Trutracs front and rear in mine.

I have plenty of suspension flex so I've never had a wheel in the air. I've been able to go up and over rocks with seemingly no wheel spin so I'm not sure if the Trutracs are actually engaging or if they just engage that easily.


Autism Family Travellers!
I have talked to a guy with true tracs in the front and rear of his JK unlimited. Drove it all winter with no issues. I am probably going to put them in my JK axles and in the rear of my suburban as well. Keep the front open on that one. My lifted avalanche will be open front and rear.


West slope, N. Ser. Nev.
This has been a long running, reoccurring thread; as well it should be. The OP mentioned his rig and driving style and a few have actually addressed those specifics. It's good to hear all the feedback from the different smaller 4x4's, but dealing with his specific set up (near and dear to my heart as I'm in the same predicament), namely traction aides for a front diff. on a heavy truck with a camper. As a long time jeeper, small j, (I've had 14, 4x4's) with L.S.'s and Lockers of all descriptions, I can say that a big heavy rig like my truck camper (see sig) is a different animal, entirely. I just sold my CJ-8 RokHugr which had ARB's front/rear and always had woes with the lines and leaking, albeit no woes with traction. I've had every other kind except the lunch box,e-locker, Eaton true trac, and an Ox.
The sprung weight on the drive wheels is the concern. I have a relatively lightweight hard side truck camper (1845#, wet) on a 2 series Dodge Cummins truck. The truck weighs 7100 pounds (with 15K winch). Fully loaded, the assembly is somewhere over 10K pounds. I purposely ordered it new with no traction aides so as to have a clean slate from which to choose traction aides at a later date. After a lot of searching, mainly on the Dodge Diesel sites, I chose the Power Lok for the rear Dana 80, 35 spline axle. Why? Those cone shaped clutches. They can be assembled with a lot of preload making the empty truck's rear wheels 'chirp' on sharp turns from a stop. And they hold up under that 7K pound of weight on the rear axle. So, a bit more 'hold' before they let go. And that's is the rub. They let go but not with a bang. It reminds me of the conehead line, "Resistance is futile". Full, mechanical lockers on anything that heavy is a mistake, imho. It's important to know where I wheel with the truck camper, aka: XTC. We live at 4K feet on the West Slope of the Sierra Nevada and that's our playground; both east and west sides. Lot's of snow; loose granite scree; sand dunes; rough dirt roads at high elevation. Here we are going up a bench in Goler Wash in Death Valley:

The only one I wanted to completely steer away from was the Trac-loc (aka: trashlok) having eaten (not Eaton) a bunch of these on Jeeps and Scouts over the years.
So with the rear axle where I wanted it, I move to the front. I installed a Spyn-tec free spin selectable front hub assembly which includes Dana 70, 35 spline outer axle stubs, Dana 70 interior locking hubs, and larger, wider spaced, serviceable bearings to replace the failure prone Chrysler unit bearing assy. My axle guru asked me if I wanted to put a Eaton True-trac L.S., gear driven diff in there while we were at it. I said I would have to do more investigating. Well, the search led to this thread, among others, and I will be ordering an Eaton True trac for the front D-60/70.
A heavy truck camper requires a very specific set of requirements for front axle traction aides. Here's hoping the True-trac lives up to those requirements.
regards, as always, jefe
Last edited: