TM 9-2320-280-34P
This task covers:
a. Oil Pressure Diagnostic Test
b. Control Valve and Governor Line Pressure
Test
INITIAL SETUP:
Tools
Equipment Condition
General mechanic's tool kit:
* Transmission fluid at proper level
automotive (Appendix G, Item 1)
(TM 9-2320-280-20).
* Adjust manual shift linkage (TM 9-2320-280-20).
Test Equipment
* Adjust modulator cable (TM 9-2320-280-20).
Pressure gauge 0-300 psi (Appendix G, Item 40)
General Safety Instructions
Manual References
Direct all personnel to stand clear of vehicle when
TM 9-2320-280-10
conducting pressure test.
TM 9-2320-280-20
Maintenance Level
Direct Support
NOTE
* The testing procedures are for use in conjunction with troubleshooting
instructions in chapter 2. Table 7-5, Oil Pressure Diagnosis, shows possible
causes of transmission malfunctions directly related to oil pressure. Note if
any reading is normal, low, or high.
* The testing procedures in this paragraph applies to vehicles with
3L80 transmissions. Refer to TM 9-2320-280-20 for 4L80-E
transmission oil pressure testing.
a. Oil Pressure Diagnostic Test
1.
Remove pipe plug (3) from line pressure port (2) on left side of transmission (1).
2.
Connect oil pressure gauge to line pressure port (2).
WARNING
Direct all personnel to stand clear of vehicle before starting engine.
Transmission slipping into gear may cause injury.
3.
Start engine (TM 9-2320-280-10) and check for leaks at connections.
4.
Bring engine to operating temperature.
5.
Place transmission shift lever in "N" (neutral) and operate engine at 1,000 rpm, note pressure
reading. Pressure should be 55-70 psi (379-483 kPa).
CAUTION
Total running time for next five tests should not exceed two minutes.
6.
Apply service brakes and place transmission shift lever in "D" (drive), and allow engine to idle, note
pressure reading. Pressure should be 60-85 psi (414-586 kPa).
7.
Apply service brakes and place transmission shift lever in "D" (drive) and operate engine at 1,000
rpm, note pressure reading. Pressure should be 60-90 psi (414-621 kPa).
8.
Apply service brakes and place transmission shift lever in "2" (low 2) and operate engine at 1,000
rpm, note pressure reading. Pressure should be 135-160 psi (931-1103 kPa).
