Designing the 6x6 Rear suspension system was my first large project for Sparks Motors. For this build I designed a Non-Triangulated 4 link suspension on air bags using the factory F-450 axle assembly so that all the abs and traction control systems would still function properly.  The pinion offset on the factory axle would not allow for a pass through driveshaft design to power the second axle. To overcome this issue I designed a SCS Transfer case to bolt to the trucks frame and split power between the two axles.  The lower output of the SCS case powers the first axle while the upper output powers a pass-over driveshaft assembly with a carrier bearing on the top of the first axle, to feed power to the second axle.  I used SolidWorks to fully model a dynamic assembly of the rear of the F450. This allowed me to test cycle the suspension system and find any interference issues before the first part was ever cut out.