Table 2-1. Mechanical Troubleshooting (Contd). h t TM 9-2320-361-34 MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION Step 2. Check boring case. Remove inspection cover from boring case. Operate earth boring machine with feed engaged and drive in neutral (TM9-2320-361-10). a. If no internal gear movement is evident, replace or repair intermediate gear assembly (para. 15-42). b. If internal gear movement is evident, remove boring case from intermediate case and replace or repair boring case (para. 15-38). END OF TESTING! 61. EARTH BORING MACHINE BRAKE INOPERATIVE Replace or repair defective clutch brake case assembly (para. END OF TESTING! 62. EARTH BORING MACHINE WILL NOT MOVE VERTICALLY 15-44). Step 1. Check power leveler. Operate power leveler vertical control (TM9-2320-361-10). Observe power leveler output shaft rotation. If power leveler top output shaft does not rotate, remove power leveler and replace or repair (para. 15-41). CAUTION When power leveler-to-intermediate case drive gear is damaged, intermediate case gear should be checked for damage or defects. Failure to check intermediate case gears may damage new power leveler drive gear. Step 2. Replace or repair defective intermediate case gears (para. 15-42). END OF TESTING! 63. EARTH BORING MACHINE WILL NOT MOVE HORIZONTALLY Perform troubleshooting malfunction 62. END OF TESTING! 64. EARTH BORING MACHINE EXCESSIVELY NOISY Step 1. Check backlash between feed idler gear and rack feed spur pinion gear (para. 15-43). If backlash is incorrect, adjust shims on boring case gears (para. 15-38). Step 2. Check earth boring machine internal gears backlash (paras. 15-41 through 15-42). If backlash is incorrect, adjust shims on boring case gears (paras. 15-38 through 15-42). END OF TESTING! 2-28