Contents: Examination ⇓ Analysis of the test results ⇓
The test is carried out to determine the maximum rotation frequency of the engine crankshaft with the output shaft of the gearbox completely stopped in the D and R ranges. The value of this frequency can be used to determine the operability of the torque converter, freewheel clutches, as well as the presence of slip in some friction elements of the gearbox control.
Examination
Check the oil level and temperature (80-100°C) and the engine coolant temperature (80-100°C).
Place blocks under the rear wheels.
With the parking brake fully applied and the brake pedal fully depressed, start the engine.
Set the gear selector lever to position D, press the accelerator pedal all the way down and determine the engine speed at this moment.
Control lever position
Caution: Do not hold the accelerator pedal for more than eight seconds.
After each check, move the selector lever to position N and run the engine at 1000 rpm until the transmission fluid temperature reaches the operating value, after which the next check can be carried out,
Repeat the same check for the R selector lever position.
Analysis of the test results
If the engine crankshaft speed during testing in ranges D and R is greater than the maximum value (3000 rpm), then this speaks about:
- low pressure in the main line;
- slipping of the brake of the first gear and reverse gear.
If the engine crankshaft speed is higher than the nominal value only in the D range, this indicates slippage of the downshift clutch.
If the engine crankshaft speed is higher than the nominal value only in the R range, this indicates that the reverse clutch is slipping.
If the engine crankshaft speed in ranges D and R is less than the minimum nominal value, this indicates:
- torque converter malfunctions;
- engine malfunctions (insufficient power).