TM 10-3930-669-20 CHAPTER 9 FINAL DRIVE MAINTENANCE Para Contents Page 9-1 Introduction ...........................................................................................................................................9-1 9-2 Driveshaft Replacement/Repair.............................................................................................................9-2 9-1.    INTRODUCTION. This  chapter  contains  maintenance  instructions  for  removing,  replacing,  repairing,  installing,  and  adjusting  final  drive components authorized by the Maintenance Allocation Chart (MAC) at the Unit Maintenance level. 9-1