TORQUE CONVERTER STALL TEST


This test measures the maximum engine speed at the time the torque converter stalls with the selector lever in the D or R position. With this test, the holding abilities of the clutch and brake that are incorporated in the transmission can be checked.
warning For safety, operators must not stand in front of and at the rear of the vehicle during this test.
1.Check the CVT fluid level, CVT fluid temperature, and engine coolant temperature.

  • CVT fluid level: In the "HOT" range on the oil level gauge
  • CVT fluid temperature: 60 to 70°C
  • Engine coolant temperature: 80 to 100°C
note Use M.U.T.-III. to measure the CVT fluid temperature.
2.Operate the parking brake securely, and then chock the wheels.
3.Start the engine.
4.
caution
  • Do not maintain the WOT condition for 5 seconds or longer.
  • When continuing the stall test, make sure that the fluid temperature does not exceed 70°C. If the CVT fluid temperature exceeds 70°C, run the engine at around 1,000 r/min for 1 minute or longer to lower the CVT fluid temperature to 70°C or less.
Move the selector lever to the D range and fully depress the accelerator pedal. Quickly read the maximum engine speed at this time.
Standard value - Stall speed: Approximately 2,300 r/min
5.Move the selector lever to the R range, and then repeat the previous step.
Standard value - Stall speed: Approximately 2,300 r/min

JUDGEMENT OF TORQUE CONVERTER STALL TEST RESULTS

  1. Stall speed is high when the selector lever is in both D and R ranges.

    • Line pressure is low.
    • Malfunction of the primary pulley
    • Malfunction of the secondary pulley
    • Malfunction of the steel belt
  2. Stall speed is high only when the selector lever is in the D ranges.

    • Malfunction of the low brake
  3. Stall speed is high only when the selector lever is in the R ranges.

    • Malfunction of the reverse brake
  4. Stall speed is low when the selector lever is in both D and R ranges.

    • Malfunction of the engine system