Fully braked test (stall test)
This test checks the performance of the gearbox and engine by measuring the speed at maximum load on the ranges "D" And "R".
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 vehicle, and the second should carry out the test itself inside the vehicle.
1. Measurement of braking speed:
- A) Block all wheels with blocks.
- b) Connect a tachometer.
- V) Apply the parking brake.
- G) Press the brake pedal hard with your left foot.
- d) Start the engine.
- e) Move the gear selector to the position "D". Fully depress the accelerator pedal Quickly read the tachometer readings and compare them with the prescribed values.
Rotational speed with a fully braked vehicle:
- Models before 1996:
- А240Е, А241Е 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
- А540Н 2220-2520 rpm
Caution: If the rear wheels start spinning before the RPM reaches the required value for this test, then release the accelerator pedal and stop the test.
- and) Repeat the test with the selector position in the range "R".
2. Analysis of the test results.
- A) If the speed for both cases is the same, but less than required, then either the engine does not develop full power, or the freewheel of the torque converter reactor is damaged.
- b) If the speed is in the range "D" higher than required, then:
- too low pressure in the main line,
- there is a slip in the forward clutch,
- defective freewheel No. 2,
- (except A132L) the freewheel of the lowering planetary gear set is faulty.
- V) If the speed in the range 'R'* 1 is higher than required:
- too low pressure in the main line,
- there is a slip in the reverse clutch,
- slippage in the brake of the first gear and reverse gear,
- (except A132L) the freewheel of the lowering planetary gear set is defective.
- G) If the 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 of the lowering planetary gear set is faulty.
Checking the switching delay time
If, with the engine idling, move the selector to the position "D" or "R", then it will take some time until you feel a slight push. By the magnitude of this delay, one can judge the serviceability of the lock-up clutch of the lowering planetary gear set (except A132L), forward clutches, reverse clutches and brakes for first and reverse gears.
Note:
- Carry out the check at normal operating temperature of the working fluid (50-80°C).
- Carry out three checks and then determine the average first gear engagement delay time
- At least one minute must elapse between checks.
1. Measure the gear shift delay time:
- A) Apply the parking brake.
- b) Start the engine and check the idle speed.
- V) Move selector out of position "N" V "D" and measure the time until the transmission is switched on. Delay time less than 1.2 sec.
- G) Move selector out of position "N" V "R" and measure the time until the transmission is switched on. Delay time less than 1.5 sec.
2. Analysis of the test results.
- A) If the switching time "N→D" more than required:
- too low pressure in the main line,
- forward clutch wear,
- (except A132L) the clutch of the lowering planetary gear set is faulty.
- b) If the switching time "N→R" more than required:
- too low pressure in the main line,
- reverse clutch wear
- wear of the brake of the first gear and reverse gear,
- (except A132L) the clutch of the lowering planetary gear set is defective.