With its open carrier and two-pinion design, the stock differential is weak in addition to giving poor traction on uneven or slippery surfaces.

Another standard differential breaks from wear and tear. Note that the pin that holds the two pinion gears is broken and one end of the pin protrudes from the carrier. Unforunately, this is all to common on the stock differentials. The harder the trail, the more spinning and bouncing one must necessarily do to overcome obstacles. This puts a tremendous amount of strain on all parts of the vehicle, but especially the differential. If one wheel is spinning and suddenly receives traction, the torque is violently sent to the opposing wheel on the axle. This is the result.

In addition to being burdened with a weak pin, the factory differential is also plagued with a weak carrier. The carrier is cut out on both sides to permit easy installation of the spider gears and the side gears. However, the holes substantially weaken the carrier and permit breakage under severe conditions.

With its solid carrier, the Detroit Locker is approximately twice as strong as the factory differential. The Detoit Locker is strong enough that some other component in the driveline will most likely break before the Detroit Locker will.

Here is a Detoit Locker without the Timken bearings pressed onto the carrier. We recommend the fitment of new carrier bearings for all replacmeent differentials as the factory differential bearings are usually not concentric. Furthermore, removal of the carrier bearings is time-consuming and may damage the bearings. We believe that it is far better to press on new carrier bearings with every replacement. Cost of the pressed-on bearings is only $40 per differential.

Here the carrier bearings are pressed onto the Detroit Locker's carrier. The bearings' races are not pictured here, but are included with every differential.

The Detroit Locker is a drop-in replacement for the factory differential. The 10 holes for the ring gear exactly match those of the factory differential (Detroit Locker on the left, standard differential on the right). No modification to either the Detroit Locker, the ring gear, or the axle's third member is required for a proper installation of the Detroit Locker.

Here are some cutaway models of the Detroit Locker. Note that all Detroit Lockers come equipped with two cross pins rather than one, as well as solid differntiar carriers. How does the Detroit Locker operate? The standard running mode for the Detroit Locker is to operate in a locked condition. The Detroit Locker then unlocks when differentiation is required, such as when the vehicle is turning. When differentiation is required, the the two dog clutches on either side of the spider assembly spread apart and permit the unit to unlock. One can simulate this unlocking on Tractech's demonstration model by turning one wheel one way and the other wheel the other way. In such case, the dog clutches separate and the unit unlocks. When both wheels are turned in the same direction, the unit remains rigidly locked. The Detroit Locker works in both forward and reverse.

Unlike with some other locking differentials, the Detroit Locker is completely self-contained and requires no wires, cables, or air hoses to operate. Accordingly, the Detroit Locker is extremely reliable. The Detroit Locker also does not require special lubricants or friction modifiers. Just pour 90wt gear oil into your axle and you are ready to roll. The Detroit Locker requires no more maintainence than your factory differential.

Unlike the Detroit Locker, the Truetrac is a limited-slip differential and is suitable for both front and rear applications. Like the Detroit Locker, the Truetrac is equipped with a solid differential carrier for maximum strength. A Truetrac is approximately twice as strong as the factory differential.

How does the Truetrac operate? The Truetrac operates like an open differential in high-traction conditions. On low-traction surfaces, the helical side gears prevent one side from spinning out of control while the other side remains stationary, as often occurs with an open differential. During times of severe differntiation when one side of the axle wants to spin out of control, the helical worm gears are pushed away from the larger helical gears and pushed into the carrier. The additional resistance on the side with less traction diverts torque to the other side of the axle.

Like the Detroit Locker, the Truetrac is a drop-in replacement for the factory differential. No modification of the Truetrac, ring gear, or third member is required for a proper installation of the Truetrac.

As with the Detroit, we highly recommend the fitment of new Timken bearings rather than pulling the worn and uneven factory bearings from your open differential. The minimal cost is small insurance.

Expedition Exchange Incorporated
20775 South Western Avenue, Unit 102
Torrance, CA 90501
Telephone: (310) 618-1875

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