Torque Converter Stall Test

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, starter motor and one-way clutch operation and the holding performance of the clutches and brakes in the transmission.

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: 80 - 100°C
- Engine coolant temperature: 80100°C
2) Check both rear wheels (left and right).
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 eight seconds.
2. If carrying out the stall test two or more times, move the selector lever to the N position and run the engine at 1,000 r/min to let the automatic transmission fluid cool down before carrying out subsequent tests.

Standard value
Stall speed: 2,100 - 2,900 r/min
6) Move the selector lever to the R position and carry out the same test again.
Standard value
Stall speed: 2,100 - 2,900 r/min

TORQUE CONVERTER STALL TEST JUDGEMENT RESULTS
a. Stall speed is too high in both D and R ranges
- Low line pressure
- Low & reverse brake slippage
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
- Insufficient engine output