TM-9-2320-280-34 HMMWV Direct Support & General Support Maintenance Manual Download
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TM 9-2320-280-34 Table 2-1. Mechanical Troubleshooting (Cont'd) MALFUNCTION TEST OR INSPECTION 20. 2-3 SHIFT SOFT OR SUPS Step 1. If oil pressure in 'D" (drive) at 1000 rpm is low, proceed to step 2. If oil pressure is normal, proceed to step 4. Step 2. Perform steps 7 through 10 of malfunction 16. Step 3. Perform steps 4 through 9 of malfunction 17. Step 4. Perform steps 8 and 9 of malfunction 18. Step 5. Check front servo for broken or missing spring and leak at servo pin. Repair front servo (chapter 17) if damaged. Step 6. Air check direct clutch piston for proper operation. If piston exhibits excessive leakage, proceed to step 7. If operation is normal, proceed to step 8. Step 7. Check direct clutch piston, plates, and release springs for damage or incorrect assembly. Repair intermediate clutch (para. 17-8) if damaged. Step 8. Check transmission case passages for leaks. Replace transmission (para. 7-6) if case is damaged. END OF TESTING! 21. 2-3 SHIFT FIRM OR ROUGH Step 1. If oil pressure in "D' (drive) at 1000 rpm is normal, proceed to step 2. If oil pressure is high, proceed to step 5. Step 2. Check front accumulator for damaged piston, rings, and broken or missing spring; check valve to accumulator feed for obstructions. Replace control valve (chapter 17) if damaged. Step 3. Air check direct clutch piston for leak to outer area of clutch piston; check center piston seal for damage. Repair direct clutch (para. 17-8) if damaged. Step 4. Check center support and second oil ring for damage. Repair center support (para. 17-9) if damaged. Step 5. Perform steps 7 through 10 of malfunction 16. Step 6. Perform steps 7 through 10 of malfunction 18. END OF TESTING! 22. NO ENGINE BRAKING - SECOND GEAR Step 1. Check front servo piston for leaking oil rings and damaged piston. Replace damaged components (chapter 17). Step 2. Check front accumulator piston for leaking oil rings and damaged piston. Replace control valve (chapter 17) if damaged. Step 3. Check front band for damage and proper installation. Replace front band (chapter 17) if damaged. END OF TESTING! 23. NO ENGINE BRAKING - FIRST GEAR Step 1. Check for missing or incorrectly installed check balls. Replace missing check balls (chapter 17). Step 2. Check transmission case for damage at check ball locations. Replace transmission (para. 7-6) if damaged. Step 3. Check rear servo for leaking oil seal rings and damaged piston. Repair rear servo (para. 17-11) if damaged. Step 4. Check rear band apply pin for proper length. Replace pin (chapter 17) if length is not correct. Step 5. Check rear band for damage and proper installation. Replace rear band (chapter 17) if damaged. END OF TESTING! 2-10