Redesigned super-strong BACKSIDE bulkheads are narrower to move the arms more into centerline to generate more traction and also to provide a greater selection of track width adjustment. The bulkheads have a fantastic fit on updated differential and they are strengthened to boost the dependability. The XB4 bulkheads allow super-fast & effortless diff trade and servicing by dismounting just 4 screws from the front side of the bulkhead and bottom associated with framework. This super-fast diff access can be obtained at both front & rear. The bulkheads have actually minimized ball-bearing play, leading to increased gear teeth lifespan and minimized gear stripping.