Two pairs of springs (inners and outers) hold the two drivers apart. The long, thin springs were inserted through the short ones as shown.
The two drivers were held apart with a screwdriver, and the passenger-side wheel was rotated about a quarter turn until the spring slots were exposed. The springs were then carefully inserted using a screwdriver to ensure that the inner spring was fully seated. While again keeping the drivers apart with a screwdriver, the wheel was rotated a half turn until the other spring slots were exposed. The second set of springs was then installed.
At this stage the gap between the drivers had to be checked. Powertrax provides a check block with the No-Slip unit to check this. The narrow side of the check block must be able to be insert between the drivers, but the wide side of the check block should not. if the gap is too wide or too narrow, something is most likely wrong with either the installation or the differential case. Either way, it needs to be checked. Ours checked out okay, so the ring gear-side axle was then pushed in and the C-clip installed through the opening in the driver.
Both wheels were then carefully rotated backwards about a quarter of a turn to expose the pinion shaft opening and Cucu felt through to ensure that all eight saddle springs were fully seated and that the spacers and drivers were fully engaged with the couplers. Everything checked out, so the case was rotated a quarterturn forward to align the pinion shaft opening with the driver saddles. Then, using the retaining bolt as a handle, he inserted the shaft into the differential. it takes a little pressure to pass the shaft by the springs but no more than you should be able to do by hand. NEVER use a hammer, if one is needed, something is wrong.
Once the shaft was installed, the retaining bolt was installed to hold it in place. After a couple of quick tests to confirm the unit was working properly, the differential cover was installed using silicon in place of the gasket and some new fluid was added. No special oil additives were required because the unit is all gear: There are no frictional clutches.
We then took the car back out, strapped it to the pole and scale, and placed the right wheel and tire back onto the zerotraction rollers. What a difference this time: The left tire was smoking and trying to pull the pole out of the ground. The scale reading this time was 980 pounds of pulling force. That's 48 times the pulling force of the open differential. If only all of our modifications were as easy to do as Powertrax's No-Slip Traction System and had improvements like that.Not bad for less than an hour's work.