TM 9-2320-272-24-2
Table 4-1. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
41. TRANSFER CASE WILL NOT STAY IN GEAR
Step 1. Check shift linkage adjustment.
Adjust shift linkage if necessary (para. 4-88).
Step 2. Remove interlock air cylinder (para. 4-83) and check if pushrod is binding.
a. If binding in interlock air cylinder or transfer case, clean ports and pushrod, and
reinstall.
b. If malfunction continues, go to step 3.
Step 3. Replace transfer case (para. 4-94 or 4-95).
END OF TESTING!
42. EXCESSIVE NOISE DURING OPERATION
Replace transfer case (para. 4-94 or 4-95).
END OF TESTING!
43. LUBRICATION LEAKS
Step 1. Check for defective seals or gaskets.
If defective, replace seals or gaskets (para. 4-93 or 5-63).
Step 2. Check for cracked transfer case.
Replace transfer case (para. 4-94 or 4-95).
END OF TESTING!
AIR COMPRESSOR
44. LOW AIR PRESSURE (NO AIR LEAKS, GOVERNOR PROPERLY ADJUSTED AND OPERATIVE)
Step 1. Remove unloader valve and unloader valve spring from compressor and inspect for wear and
damage.
Replace worn unloader valve spring (para. 4-31 or 4-52).
Step 2. If pressure is still low, replace air compressor (para. 3-206 or 4-31).
END OF TESTING!
45. AIR COMPRESSOR PASSES EXCESSIVE OIL (EXCESSIVE OIL BLED FROM AIR RESERVOIRS)
Drain air reservoirs (TM 9-2320-272-10) and check for evidence of oil.
a. If oil is present, replace air compressor (para. 3-206 or 4-31).
b. On M939A2 series vehicles, service air dryer filter element (para. 3-465).
END OF TESTING!
46. AIR COMPRESSOR DOES NOT UNLOAD (AIR GOVERNOR ADJUSTED AND OPERATIVE)
Remove unloader valve and unloader valve spring from compressor and inspect for wear and
damage.
Replace worn unloader valve spring (para. 4-31 or 4-52).
END OF TESTING!
4-12
