POWERTRAX No-Slip Traction System The POWERTRAX Traction Systems are the only differential that offers the maximum traction performance of a locking differential with the smoothness of a limited-slip/posi differential. It delivers power to both wheels through intermeshing teeth in such a way that one wheel cannot be powered ahead of the other. A specially contoured saddle ensures direct engagement of the intermeshing teeth. The Powertrax System features a precision synchronization mechanism that holds the driver and coupler disengaged throughout a turn, so the unit remains quiet and operates smoothly. In addition, the springs mounted in the saddle (that impinge on the pinion cross shaft) and the turning resistance of the synchronization mechanism help damp out backlash effects. As a result, the Powertrax System's operation is virtually unnoticeable to the vehicle driver until its extreme traction performance is required. Installation These are the steps necessary to install a Powertrax No-Slip Traction System in a Ford Explorer Sport Trac rear open differential. This should help anyone see what is all involved in this process. It was fairly easy and completed with simple tools. But care must be taken since you are changing out parts in your driveline. Step 1: Put the transmission in gear (or park) and turn off the engine. Step 2: Set the parking brake. Step 3: You blocks to ensure that the vehicle will not roll. Step 4: Jack the vehicle up and place on jack stands. Step 5: Put the transmission in neutral and release the parking brake.
Step 6: Remove the differential cover and drain fluid. Clean the cover and housing sealing surface. Here is what the differential will look like when the cover is removed. I left the sway bar in place but it may be easier if removed. Step 7: Expose the pinion shaft; remove the retaining bolt/roll pin and shaft. You can see the pinion shaft here which is the large shaft running down through the middle of the differential. And the retaining bolt on the right side. It runs perpendicular to the shaft and holds the shaft in place.
Here you can see the differential with the pinion shaft and retaining bolt removed. Step 8: Push both axles inward and remove both c-clips. Here is what the differential will look like once the axles are removed. I did not get pictures of the c-clips that needed to be removed. It is fairly simple to do and once you get to this point you will see the clips on the end of the axles. They just need to be slid off of them. Note: It may be necessary to remove wheels and disc brake calipers.
Step 9: Remove both spider gears and their thrust washers. Here is a picture of the spider gears removed. They are the small gears that are on the top and bottom of the differential in this position. Be sure that you remove both thrust washers. They are the thin washers that ride on the round portion of the spider gears. Step 10: Pull the passenger side axle shaft out approximately 6. Remove the side gears and their thrust washers. You can see the axle here and both side gears removed.
Step 11: Verify that the gaps in the coupler teeth are aligned with gaps in the synchro ring. Place the coupler in a vise and active spacer if necessary. Apply wheel bearing grease to driver teeth and spacer. Apply wheel bearing grease to saddle springs and seat in holes. Here you can see that the driver teeth and spacers are greased. Also you can see that there are four saddle spring greased and set into the holes. Step 12: Install couplers inside the differential case, ring gear side first. Install the c-clip on the ring gear side axle shaft only. Make sure that the paddle opening which is the section with the widest gap, in ring gear side synchro ring is facing away from you. Here you can see both synchro gears and spacer installed on both sides.
Step 13: Insert the non-slotted spacer into the non-slotted driver. Seat the spacer paddle at the paddle opening in driver which is missing the extended tooth. Insert the driver/spacer, making sure that the spacer paddle is facing out away from you. Verify that the spacer paddle is aligned with paddle opening in synchro ring and press diver/spacer down onto coupler. Driver teeth should be fully engaged all the way around. Here is the non-slotted side driver installed Step 14: Insert the slotted spacer into the slotted driver. Seat the spacer paddle at the paddle opening in driver which is missing the extended tooth. Verify that the paddle opening which is the widest gap, in the other synchro ring is facing towards you. Install the slotted driver/spacer making sure that the paddle is pointing towards you. Verify spacer paddle is aligned with the paddle opening in synchro ring and press down on driver/spacer to seat on coupler; driver teeth should be fully engaged. Here you can see both drivers installed.
Step 15: Place the two inner springs inside the two outer springs. Compress inner spring assembly into slot. Visually inspect notches in spring slot to make sure inner spring is fully seated. Here are the springs in their fully seated position. Step 16: While keeping both drivers wedged in engagement with couplers rotate driver s side wheel forward 180 degrees to reveal spring slot on other side. Compress inners spring assembly into second slot. Visually inspect notches to make sure inner spring is fully seated. Here is the other spring assembly fully seated.
Step 17: Check the gap between drivers using the supplied check block. The narrow side of the block should fit between the drivers, but the wider side should not fit. Step 18: Push the passenger side axle shaft inward through the coupler as far as it will go. Making sure drivers stay engaged with couplers, carefully rotate wheels until c-clip clot is accessible. Verify c-clip groove on axle is accessible through c-clip clots on driver and spacer. Insert the second c-clip through the c-clip slot in driver onto axle shaft; pull axle shaft out to seat clip. Making sure the drivers stay engaged with couplers, carefully rotate both wheels backwards to expose pinion shaft opening. Feel through pinion shaft opening and verify both spacers and drivers are fully seated onto couplers. Verify that all 8 saddle springs are fully seated in the holes. Keeping the couplers and drivers stationary, rotate the case ¼ turn forward to align pinion shaft opening with driver saddles. Using the retaining bolt/roll-pin as a handle,
rotate the shaft into the differential. Press hard while twisting to pass by the springs. Insert retaining bolt/roll-pin into case/shaft. Tighten retaining bolt firmly. Here you can see the shaft in place and the retaining bolt in position to be tightened. Step 19: Put the transmission in gear Step 20: Turn driver s side wheel forward and hold against driveline. Step 21: Passenger side wheel should not be able to rotate in the same direction. Step 22: Passenger wheel should rotate freely in opposite direction. Step 23: Repeat the test for both wheels in both directions. Step 23: Install differential cover with gasket sealant. Add differential fluid Step 24: Set the parking brake. Be sure that the transmission is in gear or park Step 25: Remove jack stands, lower vehicle, and then remove blocks.
There is a nominal 50-mile break in period. There might be slight roughness and sounds immediately after installation. After you are sure that the vehicle is performing as it should, go out and enjoy the increased traction that you now have available. As with any project, you must remember that you are doing this on your own. I can not be held responsible for anything. This should only be used as a guide and nothing more. This project will help you decide if this is something you would be willing to do. Even though it only requires simple tools and a couple of hours of work it is not an easy project.