TM 10-3930-660-34 CHAPTER 9 REAR AXLE  MAINTENANCE Section I.  DESCRIPTION AND DATA 9-1.  GENERAL. Front axle maintenance procedures not covered in this section may be found in TM10-3930-660-20. 9-2.  PRINCIPLES OF OPERATION. a. Differential.  The rear differential provides the primary drive gear reduction.  It is a single reduction carrier and is manufactured by Rockwell.  This carrier has a bevel drive pinion (1) and ring gear (2) set and bevel gears (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.  When the carrier operates,  there is normal differential action between the wheels all the time. 9-1