Keeping in mind the theory that power finds the weakest link in the drivetrain, we’re upgrading Sleeper‘s 8.8 rear with a bulletproof axle/differential package from Moser Engineering. While 31-spline axles (with C-clips) are a common step up over the OEM 28-spline sticks, the difference maker in this arrangement is Moser’s new Wavetrac differential (PN 5W8831). The gear-driven Wavetrac will help improve Cheaper Sleeper’s grip in low-traction conditions on the freeway (or if we take it autocrossing) by automatically increasing axle load internally when it’s required. At or near zero load, the axles (and each side gear in the Wavetrac) start to turn at different speeds. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart and create enough internal load within the differential to eliminate the zero-axle-load condition and apply torque to the wheel that has the most grip.