Thought y'all might like this, a TrueTrac brochure.

More on our beloved TrueTracs

This is from the June 05 JPMagazine. Awesome issue, with lots of locker, diff, rearend info.

Detroit TrueTrac

What it is: The Truetrac is a gear-driven limited slip that requires no special friction modifiers to operate. Under power, torque is sent to both tires unless there's an excessive amount of resistance on one, then it will spin.

Street Characteristics: The Truetrac is very unobtrusive on the street. When gassed in a corner or turn, you may feel the slightest pull, but there's no jerking or violent engagement of any sort. When under heavy throttle in a turn, the inside tire will bark a little, but not under normal driving conditions. The turning radius and tight maneuvers are totally unaffected (ed-nobody told them 'bout us !!)

On The Trail: The Truetrac offers near locker-like traction in all but the gnarliest terrain. We've found that modulating the brakes a bit can help keep one tire from spinning when the suspension is crossed up. You can't drive as elegantly in rocks as you can with a spool or locker, but you'll have to work pretty hard to get stuck.

Advantages: Nearly invisible on the street. Great traction. Can use straight 90W gear oil. Moderately priced and great for front or rear applications.

Disadvantages: Lots of little parts inside, so it's not as strong as most full-case lockers. Not as much traction as a locker or spool.


Keep in mind these are hard-core offroaders, but they give nothing but props to the Truetrac everytime it's mentioned

Anyway, I thought it was interesting....

This message has been edited. Last edited by: MrQuadrasteer,

These are great diffs... I think the "real" Hummers use them front & rear. No hard engagements or clutch packs to wear out and should last just about forever in "normal" use.

This message has been edited. Last edited by: Rip,

The thing gets rave reviews everywhere



Hey- let's hear it for GM, for finally making a good call !!!!



Huh... what.... Delphi ???

Ohhhhh.... that makes more sense !!!!!!!!

I think the QS rear axle uses a Dana Hydraloc (G86) rear end. Or is that just used on the Denali?

Dave, it is a G86. Some time back, I was told the QS rears used TrueTracs units as their lsd.

As time went on, with different symptoms and discussions, I really started wondering how accusrate that was, and here recently, one of the members finally got a look inside one and confirmed it was a clutch pack posi unit, not a helical unit like a TrueTrac.

I like your other post, about looking to the aftermarket for an upgrade when the time comes. It looks like the time has come for me, so I guess I'm gonna start seeing what some options are. I still dig the hell outta the TrueTrac, so that's still gonna be my first option

Although... the new line of electra-lockers are sweet, but aweful-pricey

Do all QS trucks use the same rear-end? I saw a version with 6-lug hubs on ebay (1500), but mine is 8-lug (1500HD).

I have heard Dana-60, G86, 9.75 inch...

Also, are they always limited slip? (mine is) or are there other variations like open or locking ?

This message has been edited. Last edited by: Brian Gallimore,

The 6 lug versions were the first ones out, fitted on the Sierra Denali C3 extended cab pickups... the initial models to get 4WS.

Some 2002 1/2 tons under the Silverado brand sold later that model year also had 6 lugs.

The 3/4 ton SUVs, the light 2500s, and the heavy 1500's all get the 8 lug rotors.

The Sierra Denali C3's continued to be fitted with 6 lugs until 4WS was no longer offered on the Denali pickup (as of 2004).

All Quadrasteer axles have the same type of limited slip system, regardless of 6 or 8 lug rotors.

There is no "G80" Eaton locking type differential available with Quadrasteer. Only the "G86" limited slip type differential is/was available, and in fact Quadrasteer could not be had without it.

The Detroit TrueTrac that Mr. Quadrasteer had earlier suggessted might be in the 4WS axle was completetly off the mark. The Quadrasteer axle uses clutch packs to accomplish limited slip (a total of 18 discs, 9 discs per side gear).

Neither driveaxle ratio, truck or SUV model, or rotor lugs make a difference in this limited slip feature of Quadrasteer axles. All require a special lubricant specifically released for 4WS axles only.