TM 9-2320-209-20-3-4 CHAPTER 22 NONELECTRICAL GAGES GROUP MAINTENANCE Section I. SCOPE 22-1. EQUIPMENT ITEMS COVERED. This chapter gives equipment maintenance procedures for nonelectrical gages for which there are authorized corrective main- tenance tasks at the organizational maintenance level. 22-2. EQUIPMENT ITEMS NOT COVERED. All equipment items for which corrective maintenance is authorized at the organizational maintenance level are covered in this chapter. Section II. NONELECTRICAL GAGES 22-3. TACHOMETER ASSEMBLY REMOVAL, REPAIR , AND REPLACEMENT. TOOLS : Flat tip screwdriver 3/4-inch open end wrench 7 /16-inch open end wrench 7/16-inch open end wrench l-inch open end wrench 3/8-inch open end wrench Slip joint pliers SUPPLIES : Tachometer drive plug gasket Tachometer drive adapter gasket Rubber grommet PERSONNEL : One EQUIPMENT CONDITION : Truck parked, engine off, handbrake set. a. Preliminary Procedures. (1) Disconnect battery ground cable. Refer to Part 1, para 7-58. (2) Open hood and left side panel. Refer to TM 9-2320-20%10. (3) Take off air compressor belt. Refer to Part 2, para 13-34. 22-1