Shift Point Shop Tests
Shift Point Shop TestNOTE: A shift test can be performed in-shop to check shift valve operation, governor circuits, shift delay pressures, throttle boost, and downshift valve action.
1. Raise and support rear of vehicle.
2. Disconnect and plug vacuum line to vacuum diaphragm unit.
3. Connect line from distributor vacuum tester vacuum pump to vacuum diaphragm unit.
CAUTION: Never exceed 60 mph speedometer speed.
4. Check shift valves and governor circuits as follows:
a. Apply 18 inches of vacuum to vacuum diaphragm unit.
b. Place transmission in Overdrive and make a minimum throttle 1-2, 2-3, 3-4, and lockup shift.
Shift Speed Chart:
c. If shift points are within specifications, shown in the Shift Speed Chart, 1-2, 2-3, converter clutch, and 3-4 shift valves, and governor are satisfactory. If shift points are not within specifications perform a Governor Check to isolate the problem.
CAUTION: After each test, move the selector lever to Neutral and run the engine at 1,000 RPM to cool converter.
5. Check shift delay pressures and throttle boost as follows:
a. Decrease vacuum at vacuum diaphragm unit to 0.0-2.0 inches.
b. Make a 1-2 shift test. If shift point rises to specification, throttle boost and shift delay systems are functioning properly.
CAUTION: After each test, move the selector lever to Neutral and run the engine at 1,000 RPM to cool converter.
6. Check downshift valve action as follows:
a. Leave vacuum to vacuum diaphragm unit at 0.0-2.0 inches.
b. Position downshift linkage in wide open throttle position and repeat 1-2 shift test. Speed at shift point should be higher.