Check the fluid level in the gearbox. The fluid should be warmed up (70-80°C). The engine coolant should also be warmed up (80-90°C).
Block the rear wheels by placing blocks under the wheels.
Attach the engine tachometer.
Apply the parking and service brakes.
Start the engine.
With the transmission shift lever in the "D" position, fully depress the accelerator pedal to obtain maximum engine speed. Do not hold the throttle open longer than 5 seconds to obtain maximum engine speed. If more than one lock-up test is required, run the engine for about 2 minutes in neutral at 1000 rpm between tests to cool the transmission fluid.
ATTENTION: Critical engine speed when braking the torque converter during testing: 2500±300 rpm.
Set the gearshift lever to the "R" position and perform the test using the above-described method. If the critical speed is higher than normal, there is slippage of the rear clutch or overrunning clutch of the gearbox (lever position "D").
If the critical speed is higher than normal, there is slippage of the front clutch of the transmission or the low and reverse brake (lever position "R"). In these cases, conduct tests to determine the cause of slippage.
If the critical engine speed is below normal with the lever in the "D" and "R" positions, it may be due to insufficient engine power or a faulty torque converter. Check for misfires in the engine, correct ignition timing, valve clearances, etc. If everything is OK with the engine, the torque converter is faulty.
(The article is based on data from the website: MITSUBISHIMAN.ru)