TORQUE CONVERTER STALL CHECK


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.
1.
warning For safety, operators must not stand in front of and at the rear of the vehicle during this test.
Check the ATF temperature.

  • ATF temperature: 50 - 80°C
  • Switches for air conditioner, lamps, and others shall be OFF.
note Use the M.U.T.-III to measure the ATF temperature.
2.Raise the vehicle.
3.Pull the parking brake lever, and then fully depress the brake pedal.
4.Start the engine.
5.
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 80°C. If the fluid temperature exceeds 80°C, perform the test after running the engine at around 1,000 r/min for 1 minute or longer and then cooling the ATF to 80°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: 2,100 ± 150 r/min
6.Move the selector lever to the R range, and then repeat the previous step.
Standard value: 2,100 ± 150 r/min

JUDGEMENT OF TORQUE CONVERTER STALL TEST RESULTS
Stall test result
 Probable cause
Both D and R are less than the standard value.
  • Insufficient engine output
  • Malfunction of one-way clutch in torque converter
Only D is higher than the standard value.
  • Line pressure is low.
  • Malfunction of clutch No.1 (slip)
  • Malfunction of one-way clutch No.3
Only R is higher than the standard value.
  • Line pressure is low.
  • Malfunction of clutch No.3 (slip)
  • Malfunction of brake No.4 (slip)
  • Malfunction of one-way clutch No.1
Both D and R are higher than the standard value.
  • Line pressure is low.
  • Oil leak in each range circuit