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Nuts & Bolts: Truetrac vs. ARB

Trenton McGeeWriterTrenton McGeePhotographer

Truetrac vs. ARB
I currently own a 2005 Jeep Unlimited. The previous owner upgraded the Jeep with 33-inch rubber, a short-arm Rubicon Express kit, an ARB up front in the stock Dana 30, and a Detroit out back in the Dana 44. Both with 4.10 gears. I have also installed a Banks turbo kit. The Jeep wheels great. It will go just about anywhere I point it. The only limitation seems to be deep ruts, where I get high-centered on the diffs or skidplates. Currently I am happy with the 33s but may go to 35 in the future.

I just hate the Detroit Locker. My Jeep gets used on the street a lot as a daily driver, and I simply can’t stand the play in the drive line from the locker. I do love the no-brainer traction the auto locker gives me (no switches to turn on), and I’m sure I could live with it if I had an auto trans, but mine is a manual. The banging and the drivetrain slop has to go. I do know that my rear diff play comes from the locker, as I have looked over everything else. I have been researching different options, and my top two are another ARB or a Detroit Truetrac. The ARB is obvious strength and select-ability, but the Truetrac is on my short list for its reputation as being almost as tight as a true locker. I understand how it works and how people use the brakes in order to get some more performance out of it; I just haven't experienced or seen what it can do. The biggest draw of the Truetrac is that there are no switches, just point and go.

My normal wheeling in southern Alberta and southeastern British Columbia includes fire roads, deep mud, deep dry ruts, washouts, loose dirt, gravel hillclimbs, snow, and ice. The majority being dry fire roads. I don't rockcrawl. With this list, I'm thinking that the majority of my limitations, where a Truetrac would show its weaknesses, would be in areas where I had to cross dry deep ruts or washouts. Do you think a Truetrac would be a good choice?
Lorne B.
Via nuts@4wheeloffroad.com

That’s a tough call. We have experience with all three differentials you’ve mentioned, and each one has its benefits. We have run Detroit Lockers (eaton.com) in almost all the off-road rigs we have owned and love their simplicity, but even the people at Eaton, the manufacturer of the Detroit Locker, will tell you that they do have their handling quirks on the street. They can also be a real handful in snow and ice, so we understand your wanting to make a change.

The main difference between the Truetrac (also manufactured by Eaton) and the ARB (arbusa.com) is that one is a limited slip while the other is a true locking differential. You are correct that a Truetrac is regarded as a tight limited slip and its all-gear design means it is less likely to wear out compared to a limited slip that uses clutches. If we had an application where we wanted to use a limited slip, the Truetrac would be at the top of the list, and we think it would perform pretty well considering your needs and uses. While both the ARB and the Truetrac are great choices, we would still lean toward the ARB mostly because you already have a compressor to run the front locker. While the Detroit tends to pop and bang on the street, you may not realize just how much traction the Detroit contributes off the pavement, traction you might end up missing if you choose the limited slip. You are correct that pushing the button on an ARB takes some getting used to and some advance planning, but this can be overcome, and having 100 percent traction on demand is hard to beat when you really need it. And since you already have the compressor and its related wiring installed, adding an ARB to the rear is going to cost about the same as a Truetrac.