Torque Converter: Testing and Inspection

TORQUE CONVERTER STALL TEST





This test measures the maximum engine speed when the selector lever is at the D or R position and the torque converter stalls to test the operation of the torque converter, stator and one-way clutch operation and the holding performance of the clutches and brakes in the transaxle.

CAUTION: Do not let anybody stand in front of or behind the vehicle while this test is being carried out.

1. Check the automatic transmission fluid level and temperature and the engine coolant temperature.
^ Fluid level: At the HOT mark on the oil level gauge
^ Fluid temperature: 70 - 80°C (158 - 176°F)
^ Engine coolant temperature: 80 - 100°C (176 - 212°F)

NOTE: Use the scan tool (MUT-II) to measure the ATF temperature.

2. Chock both rear wheels.
3. Pull the parking brake lever on, with the brake pedal fully depressed.
4. Start the engine.
5. Move the selector lever to the D position, fully depress the accelerator pedal and take a reading of the maximum engine speed at this time.

CAUTION:
1. The throttle should not be left fully open for any more than five seconds.
2. If the temperature is 80°C or higher and the stall test is then to be carried out, move the selector lever to N range and run the engine at 1,000 r/min for one minute or more so that the temperature of the ATF drops below 80°C before carrying out the stall test.
Standard value:
Stall speed: 1,900 - 2,400 r/min

6. Move the selector lever to the R position and carry out the same test again.
Standard value:
Stall speed: 1,900 - 2,400 r/min

TORQUE CONVERTER STALL TEST JUDGEMENT RESULTS
a. Stall speed is too high in both D and R ranges
^ Malfunction of torque converter (torque converter and input shaft splines are slipping)
^ Low line pressure
^ Low & reverse brake slippage and malfunction of one-way clutch
b. Stall speed is too high in D range only
^ Underdrive clutch slippage
c. Stall speed is too high in R range only
^ Reverse clutch slippage
d. Stall speed too low in both D and R ranges
^ Malfunction of torque converter (One-way clutch slipping)
^ Insufficient engine output