Tom Wilson
April 1, 2002
Compact and relatively affordable, the Powertrax No-Slip Traction System differential delivers a shark-bite grip. It can be ordered to work with 28- or 31-spline axles. Installation does not require removal of the ring-and-pinion from the differential.

Horse Sense: When first installed, the Powertrax No-Slip Traction System is one noisy, clanking son-of-a-gun, but the metal-shop noises from our differential were hugely diminished after just 100 miles of driving. A light but noticeable clack while cranking around parking lots is the definitive No-Slip Traction System noise. Otherwise, it's basically silent.

It's doubtful if any of us need help initiating a tach-twisting bench-racing session, but if you do, bring up the subject of lockers, limited slips, Traction-Loks, and all that. After all, making twin black stripes on the pavement is something the stock Mustang doesn't do all that well, and the after-market help in this area comes from all points on the mechanical and fiscal compasses.

One of the latest traction aids to hit the 8.8-inch differential is the Powertrax No-Slip Traction System. An all-steel, mechanical-locking device, the No-Slip Traction System falls into the middle of the obtainable area of the "limited-slip" spectrum at $400. It also allows a relatively easy installation-and we will qualify that overused term in a moment-because it does not require upsetting the differential's ring-and-pinion gear relationship. That means there's no backlash to adjust, no dial indicators to use, just a straight-forward wrench-and-screwdriver session. Furthermore, Powertrax positions its unit as something almost revolutionary in two-wheel-drive traction enhancement-the-noisy-as-a-blacksmith-but-absolutely-will-not-spin drive provided by a locker coupled with the less-effective, but smooth, quiet operation of a more traditional clutch-pack (Traction-Lok) or cone-type (Auburn) limited slip.

To find out for ourselves, we went to DriveTrain Direct in Corona, California. There the expert installers whipped a Powertrax No-Slip Traction System into our own '96 4.6 GT-and incidentally rebuilt our tired 8.8-inch axle when they discovered the axles were nicked, the bearings tired, the pinion seal gushing lube, and the preload gone in the gear set-can't say this car hasn't been tested.

At left is the Powertrax No-Slip Traction System driver. At right is one of the couplers that mates with the axle using the splines visible at its center. Note how the driver teeth couple both with the outer teeth on the coupler and the inner set of teeth that are part of the synchronizing mechanism.

The installation is covered in the photos and captions, but here we'll note the job goes basically as advertised. The mechanically adept enthusiast can make this a driveway install, as no special tools are required, but the job is made considerably easier with a hoist as it all takes place at periscope depth. Let us also advise the home installer to study the excellently produced and thorough instructions at length while at the comfort of the kitchen table, No-Slip Traction System in hand. A deceptively simple-looking device, the unit must be assembled in the rear axlehousing. Like a good wooden puzzle, once you understand the details it goes together easily enough, but if approached in a rush it is certain to frustrate-possibly in a major way. That said, the install highlights are to remove the rear wheels, brakes, and differential cover, pull the C-clips, and remove the axles. The differential spider (side) gears or Traction-Lok are removed. The Powertrax system is assembled piece by piece in the differ-ential carrier. Then the axles and so on, go back in.

If you wish, either stock 28-spline or stronger 31-spline No-Slip Traction Systems are available. Thus, if you are like us and desire an axle upgrade, now's the time. Don't forget the axle bearings and oil seals if they are worn, but there is no requirement to change these items for a simple Powertrax install.

What are the peculiarities of driving the No-Slip Traction System? Well, it positively locks the axles together, of that there is no doubt. Punch it hard and the system grabs the axles together, and both tires spin if you have enough steam on line. You can even make a 90-degree turn from a dead stop, spinning both tires all the way. Traction is remarkably improved, and on loose surfaces the improvement is dramatic. In short, the traction improvement is right up there with what a spool or locker delivers. Straightline enthusiasts, especially those wanting a streetable traction solution, ought to be greatly pleased.