Front HS bulkheads enable diff height adjustment using eccentric bushings. Inside the front part gearbox, the diff height has a 2mm modification range through which 1 Dot is for upper diff place. The diff height modification is a vital set-up capability that enables quick set-up adaption for either Carpet or Dirt songs. You'll find 3 various angle configurations for adjustment for the front drive train. Carpet variation runs with reduced trip height and to keep consitently the drive shafts right the differential is put in top place. Dirt version runs with top ride height also to keep the drive shafts right the differential is put in lower spot. Fits XB4'21
