Limited Slip Faceoff: Detroit TrueTrac vs. ARB Air Locker

[redthies]

I had f+r ARBs in my '03 Tundra. Loved them. If you can afford it, and want an on-board compressor anyway, it's the way to go. I used the lockers quite a bit, but the compressor saw the most use. I would start with ARB in the rear, and then add front when or if you find the need for it.

[sourdough]

How about one of those units that are L.S. until you engage to fully locked. Put it in the rear axle. If I was going to put money in my axle that's where it would go. My Tundra has a factory optioned L.S. rear axle. It's all I need for trails that are full size friendly and won't beat up my rig. I had a locked Willys CJ3a that could/did go most anywhere, but that's a whole different type of trail rig. A truck and camper rig isn't going to be lofting wheels and rock crawling, well not for very far anyways.

[locrwln]

I have had ff/rr ARB's on two rigs that were for rockcrawling, factory ff/rr lockers on two LC80 style landcruisers and the factory rear locker on a Tacoma. My current truck and camper hauler has the factory Gov-loc rear diff and I added an Eaton E-locker in the front diff. My Wrangler has the factory lockers front and rear.

On my truck after getting the front locker installed, I went out and tried it out. It took a few tries to find a spot where the factory gov-loc wouldn't get me through. I actually had to find a rutted out hill climb to find out whether the front locker was doing my any good.

I have found that while out in the backcountry with my truck/camper, I rarely use the front locker, but when I need it, I need it. Even with my camper, the front still weighs more than the rear, so that is a factor. I hit two seperate trails this last week, that I needed the front locker to get to the summit. The first one was steep rutted out, loose rocks and the second had me climbing an uneven rock ledge.

Here is a picture of the ledge, the picture doesn't do it justice, but the locker changed it from a tire spinning episode to a smooth crawling event.

And here is truck crawling up and over it.


I would recommend at least one full locker or both if you can afford it.

Jack

[Metcalf]

In my Dodge I run a factory rear Powr-lok.
In my Willys I run a rear powr-lok and a front autolocker ( Spartan lunchbox style locker )

Honestly, I think lockers are not really need as much as people think. Most people give up A LOT of performance by not airing down there tires properly. I always generally recommend that people invest in a winch before aftermarket lockers. If your vehicle comes with them stock that is great, but you WILL get stuck at some point and need recovery gear. A grumpy old man once told me, " all that fancy 'stuff' will just get you stick further from home, what you need is a winch ". This was back in my younger days when it was all about lockers, big tires, multiple transfer cases, etc. We traveled in a pack so getting a strap out of a bad situation was easy. Once you start traveling alone the requirements change.....

There will be trails or situations where even lockers won't get you where you want to go. Do you turn around at that point, or do you use the winch?

[78Bronco]

If you are going to install a locker I would recommend it be installed in the rear axle which tend to be stronger. The limited slip goes up front where you will need to have some forgiveness to protect the typically weaker front axle with u-joints, stub axles, locking hubs etc. Now if you are running solid axle D60's front and back with a smallish tire you shouldn't have much issue with a locker out front but if you have a D50 which is basically a D44 you will start breaking.

[drodio]

Wow guys, all of this feedback is super helpful. I hadn't considered prioritizing the winch over the lockers... mainly because I've already been in situations where I wished I had some level of locking diffs, but I haven't yet gotten myself into a situation where I've needed a winch. But that's definitely something to think about.

After all of the back & forth above, I've now started to lean towards an ARB locker on the rear that I can turn on & off, and nothing on the front (maybe a winch for extreme situations)... whereas before I was leaning towards a true-trac. I'd love to hear from more people who have had a TrueTrac specifically, if there are more of you out there.

As always, thanks a ton for all of your feedback & guidance; much appreciated.

[bjm206]

I have run both the ARB selectable locker (front and rear) and the TruTrac (front and rear).

The selectable locker is the ultimate in traction. Turning will be harder with the rear diff locked and sometimes impossible with the front diff locked. On slippery highly cambered roads the axle will tend to slide down the camber (off the road) with the locker engaged. Typically you will use the selectable to get through a difficult section then unlock until you need it again.

The TrueTrac (torsen) is a distant second place as far as traction goes. You will need the brakes to torque transfer anytime one side of the axle has little or no traction. Under most conditions the TrueTrac will not effect handling when engaged and it does not have nearly the same issues on slippery cambered roads.

As you probably know the speed based limited slips should not be used in the front diff as they will greatly effect steering when engaged.

Which diff works best depends on what problems you are having or which ones you are likely to see. Rocks are the domain of the selectable. Strait sections of mud and sand are best tackled with the selectable but the torsen (TrueTrac) will also usually work ok. Long sections of slippery cambered surfaces seem best suited to the torsen (TrueTrac).

[Bergum]

Lockers and Arb's are for getting you into problems.
Winch is for getting out again... :-)

B4x4.no

[DaJudge]

I have been running a True-Trac in my front axle for 6 years. It has performed flawlessly on every surface, including smooth wet granite. The only thing I can say about it is it is picky about the fluid. I change mine once a year (more if I have taken a lot of trips) which is 8,000 to 10,000 miles, and that seems to be enough. I chose it because of price and maintenance ( no air lines to worry about, no compressor, etc.). However, for the rear of a truck I would recommend a selectable locker. I had a Ranger with a Torsen style LS in it and it was down right dangerous in slick conditions. I had to drive with a very light foot.

If you can afford it go with the ARB in the rear. The True-Trac in the front would be fine.

[Buliwyf]

My F250, while capable, needs to make some tight turns in 2wd. Even in slippery, gooey offroad conditions, I have to shift out of 4wd to make some manuevers whithout the truck hopping and jumping. Even when snow wheeling. 3 point turns are normal for big trucks. I'm constantly shifting the floor shifter in and out of 4x4. I allmost allways try turns in 2wd first.

Often I need more than a LS or open diff during those moments. And a ARB that's locked up would be a pain. An ARB that's open would be useless. Tight turning on a grippy but steep grassy/sandy uphill really shows the advantages of the Detroit. But it takes a while to learn to get the most out of that diff.

So I run a Detroit locker in the rear and a open diff up front.

IME on a truck as big and heavy as the F350, a rear Truetrac is not optimal. Wouldn't be much better than the stock limited slip if it was shimmed correctly (cram as many shims in as possible) and use zero friction modifier. Truetracs are the cats meow in a light wheeling Nissan Titan.

If you drive it carefully it's fine. You have to drive responsible in snow and run AT tires in the winter, but we allready do that anyway right? A Superduty with a Detroit rear and a Truetrac front will go anywhere a Superduty should. If you put anything up front, make sure it's a Trutrac, Limited Slip, or selectable. Don't put a autolocker or spool up front. Some folks have run the Detroit up front, but generally they are the types who only are in 4wd on a muddy farm road traveling in a straight line. Since I'm rarely in 4wd, I'm considering a Detroit also in my front diff, but for now, I need to spend money elsewhere instead. I rarely spin a front tire, so far the truck is a beast with just the locker in the rear.

Lockers aren't just for hardcore wheeling, they have many practical uses. My Detroit gets used every weekend and I miss it when I'm in a truck without it. My F250 has never needed a winch, I don't hardcore wheel with a truck, thats what dirtbikes like the Kawa KLR and Honda CFR450r are for.

Besides, you have that awesome Visteon/Sterling 10.25/10.5" rear axle, it can handle anything a Detroit is going to throw at it with ease. Keep in mind that in a big, long, heavy truck, with insane strong axles, the quirks of a Detroit are hardly noticable and easy to work around. That diff was born for big trucks. It might be a nightmare in a Jeep or Toyota though. I'm also assuming you have a auto transmission. Slushboxes are much smoother, Detoits hate manuals transmissions combined with daily driving.

Truetracs are great in the front of a Superduty because it's rare for a Superduty to lift a front tire. Trutracs are useless with one wheel in the air. My F250 lifts the rear tires more often, and Truetracs, even with the E brake on don't really work well enough in the big heavy trucks.