TM10-3930-660-34 CHAPTER 8 FRONT AXLE MAITENANCE Section I. DESCRIPTION AND DATA 8-1. GENERAL. Front axle maintenance procedures not covered in this section may be found in TM10-3930-660-20. 8-2.  PRINCIPLES OF OPERATION. a.  Differential.  The front differential provides the primary drive gear reduction. It is a single reduction carrier and is manufactured by Rockwell. This carrier has a hypoid drive pinion (1) and ring gear (2) set and a no-spin unit (3) in the differential assembly. A straight roller (spigot) bearing (4) is mounted on the head of the drive pinion (1). All other bearings in the carrier are tapered roller bearings. The no-spin differential unit (3) is contained in the differential case (5). When the carrier operates, the no-spin unit delivers one-hundred percent of the available power to both drive wheels, yet automatically allows normal differential action when required. 8-1