Test on a fully braked car (stall test)
This test checks the performance of the gearbox and engine by measuring the rotation speed at maximum load in the "D" and "R" ranges.
Note:
- the test should be carried out at normal operating temperature of the working fluid (50 - 80°C):
- the duration of each check should not exceed five seconds.
- the test should be carried out by two technicians: one should observe the wheels outside the car, and the other should carry out the test itself inside the car.
1. Measuring braking speed:
- a) Block all wheels with chocks.
- b) Connect the tachometer.
- c) Apply the parking brake.
- d) Press hard on the brake pedal with your left foot.
- d) Start the engine.
- e) Move the gear selector to position "D". Press the accelerator pedal all the way down. Quickly read the tachometer readings and compare them with the specified values.
Rotation speed with the vehicle fully braked:
- Models before 1996:
- A240E, A241E 2200-2500 rpm
- A241L 2050-2350 rpm
- A132L, 5E-FE 1900-2300 rpm
- Models since 1996:
- A241L 2310-2610 rpm
- A241E. 2050-2500 rpm
- A245E (4A-FE) 2050-2450 rpm
- A245E (7A-FE) 2300-2800 rpm
- A540N 2220-2520 rpm
Caution: If the rear wheels begin to spin before the RPM reaches the required value for this test, release the accelerator pedal and stop the test.
- g) Repeat the test with the selector in the "R" range.
2. Analysis of the inspection results.
- a) If the rotation speed is the same for both cases, but less than required, then either the engine does not develop full power, or the freewheel clutch of the torque converter reactor is damaged.
- b) If the rotation speed in the "D" range is higher than required, then:
- too low pressure in the main line,
- there is slippage in the forward clutch,
- freewheel clutch #2 is faulty,
- (except A132L) the freewheel clutch of the reduction planetary gear set is faulty.
- c) If the speed in the range 'R'* 1 is higher than required:
- too low pressure in the main line,
- there is slippage in the reverse clutch,
- slippage in the brakes of first gear and reverse gear,
- (except A132L) the freewheel clutch of the planetary gear reduction row is faulty.
- d) If the rotation speed is higher than required in both ranges, then:
- too low pressure in the main line,
- the level of the working fluid in the transmission does not correspond to the required value,
- (except A132L) the freewheel clutch of the reduction planetary gear set is faulty.
Checking the switching delay time
If you move the selector to the "D" or "R" position with the engine idling, some time should pass before you feel a slight jolt. The length of this delay can be used to judge the serviceability of the downshifting planetary gear locking clutch (except A132L), forward clutches, reverse clutches and brakes for first gear and reverse gear.
Note:
- Carry out the check at normal operating temperature of the working fluid (50-80°C).
- Perform three tests and then determine the average delay time for first gear engagement
- There must be at least one minute between checks.
1. Measure the gear engagement delay time:
- a) Apply the parking brake.
- b) Start the engine and check the idle speed.
- c) Move the selector from position "N" to "D" and measure the time until the gear is engaged. The delay time is less than 1.2 sec.
- d) Move the selector from position "N" to "R" and measure the time until the gear is engaged. The delay time is less than 1.5 sec.
2. Analysis of the inspection results.
- a) If the "N→D" switching time is longer than required:
- too low pressure in the main line,
- wear of the forward clutch,
- (except A132L) the planetary gear reduction clutch is faulty.
- b) If the switching time "N→R" is longer than required:
- too low pressure in the main line,
- wear of the reverse clutch,
- wear of the first gear and reverse gear brakes,
- (except A132L) the planetary gear reduction clutch is faulty.