Table 2-1, Mechanical Troubleshooting (Cont)
TEST OR INSPECTION
55. SQUEAL AT LOW SPEEDS, ESPECIALLY WHEN HOT
Remove speedometer driven gear from transfer case. (See TM 9-2320-289-20)
Inspect seal for damage. Inspect speedometer driven gear shaft to see if it is
Replace speedometer driven gear if shaft is twisted.
Remove propeller shafts from transfer case. (See TM 9-2320-289-20) Check for
damage or lack of lubrication at output shaft seals.
Lubricate seals with hydraulic fluid (Item 40, Appendix B) or replace if
56. NO UPSHIFTS, DELAYED UPSHIFTS, OR FULL THROTTLE UPSHIFTS ONLY
Disconnect downshift electrical connector from side of transmission. Operate truck
and observe upshift performance.
If upshift is normal, replace transmission downshift switch on side of
If upshift performance is still poor, perform step 2.
Connect downshift electrical connector to side of transmission. Test transmission oil
pressure with brakes applied, D (Drive), engine at 1000 rpm. (See paragraph
If oil pressure is normal; remove, disassemble, clean, and inspect governor
assembly. (See paragraph 5-5)
If oil pressure is high, perform step 3.
Test transmission oil pressure with brakes applied, N (Neutral), engine at
1000 rpm. (See paragraph 5-11)
If oil pressure is normal, perform step 4.
If oil pressure is high, perform step 5.
Check for leaking or damaged detent solenoid.
Tighten detent solenoid if loose and replace if damaged. (See paragraph 5-7)
If detent solenoid is not loose or damaged, clean transmission control valve
assembly. (See paragraph 5-7)
Check for loose or damaged vacuum lines and hoses.
Connect vacuum hoses or vacuum lines if loose and replace if damaged. (See