AUTOMATIC TRANSMISSION ± On-vehicle Service
23-44
CONVERTER STALL TEST
In this test, the engine maximum speed when the torque
converter stalls with the selector lever in the ªDº or ªRº range
is measured to check operation of the torque converter, starter
and one-way clutch and check holding performance of the
transmission clutch (including brake).
Caution
Do not stand in front or at rear of the vehicle during this
test.
1. Check the transmission fluid level. The fluid temperature
should be at the level after normal operation (70 ± 90_C).
The engine coolant temperature should also be at the
level after normal operation (80 ± 95_C).
2. Apply chocks to the rear wheels (right and left).
3. Mount an engine tachometer.
4. Apply fully the parking and service brakes.
5. Start the engine.
6. With the selector lever in the ªDº range, fully depress
the accelerator pedal and read off the engine maximum
speed.
NOTE
When doing so, do not keep the engine running with throttle
full open for more than 5 seconds. If two or more stall
tests are needed, place the selector lever in the ªNº position
and run the engine at about 1,000 r/min to allow the
transmission fluid to cool before another stall test.
Standard value: 2,320 ± 2,620 r/min
7. Place the selector lever in the ªRº range and perform
the test as above.
JUDGEMENT OF STALL TEST RESULTS
Stall speed in ªDº and ªRº range is equal to each other
but lower than the nominal value.
(1) Engine output is low.
(2) Starter one-way clutch is faulty. (Faulty torque
converter is suspected if it is lower than nominal by
more than 600 r/min)
Stall speed in ªDº range is higher than nominal. (1) Overdrive clutch slipping
(2) Overdrive one-way clutch faulty
(3) Forward clutch slipping
(4) One-way clutch No. 2 faulty
(5) Low line pressure
Stall speed in ªRº range is higher than nominal. (1) Overdrive clutch slipping
(2) Overdrive one-way clutch faulty
(3) Direct clutch slipping
(4) Brake No. 3 slipping
(5) Low line pressure
Engine
tachometer
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