Testing is performed to determine the maximum engine speed when the selector lever is set to «D» or «R», and check the operation of the torque converter, starter and one-way clutch, as well as the characteristics of the clutches and brakes.
Warning! No one should stand in front of or behind the vehicle while testing.
Order of execution
1. Before testing, check the levels of all operating fluids and, if necessary, bring them to normal levels.
- The transmission fluid level should be near the mark «NOT» on the index.
- The temperature of the transmission fluid should be between 80-100°C.
- Coolant temperature 80–100°C.
2. Place chocks under the rear wheels.
3. Apply the parking brake and depress the brake pedal.
4. Start the engine.
5. Move the selector lever to position «D». Press the brake pedal all the way down with your left foot, and gently press the accelerator pedal with your right foot. When the engine speed no longer increases, read the tachometer and release the accelerator pedal.
- 1. To exclude damage to the gearbox, test for 8 seconds.
- 2. If it is necessary to carry out more than one test with the engine running, move the selector lever to the position «N» and let the engine run at idle until the transmission fluid has cooled. Running the engine at idle speed cools the transmission fluid and prevents deterioration of its properties.
- 3. Do the same test in the position «R» selector lever.
Warning! Engine speed when testing the combined operation of the automatic transmission and the engine on a stationary vehicle (stall test):
- F4A42: 2000-2900 min-1
- A4AF3: 2200–2800 min-1
Warning! Engine speed when testing the combined operation of the automatic transmission F4A42 and the engine at a stationary vehicle (stall test): 2000–2900 min–1
Analysis of test results
1. Engine speed above specification in position «D» And «R».
- Low pressure in the pipeline.
- Slippage of brake bands in low gear and reverse gear.
- 2. Engine speed above specification only in position «D».
- Downshift clutch slip.
3. If the engine speed is above the specification only in position «R».
- Reverse clutch slip.
4. If the engine speed is below the specification in position «D» And «R».
- Torque converter damage.
- Insufficient engine power.