Stall Test

STALL TEST

NOTE: The stall test is made at full throttle only in all forward speeds and reverse to determine if the band and clutches are holding properly.

CAUTION: When making this test, do not hold the throttle open for more than five seconds at a time. Then move the selector lever to Neutral for approximately 15 seconds and run the engine at fast idle to cool the converter before making the next test

1. Connect a tachometer and start the engine to allow it to reach its normal operating temperature.

WARNING: Apply the service brakes as the parking brake will not remain on (if equipped with vacuum release) when the selector lever is moved to a drive position.

2. With the selector lever at D or D2, press the accelerator to the floor and note the engine speed.
a. In D or D2 with car standing still, the forward clutch and one-way clutch are engaged at all accelerator pedal positions.
b. In 2 or D with car standing still, the intermediate band and forward clutch are engaged at all accelerator pedal positions.
3. In 1 or L the forward clutch and low-reverse clutch are applied. If the intermediate band slips, the one-way clutch will hold, but operation will be for first gear.
4. In R the reverse high clutch and low-reverse clutch are applied.

Stall Speed Limits:

5. If engine speed exceeds the maximum limits given in the Stall Speed Limits table, release the accelerator immediately because clutch or band slippage is indicated. The band or clutch that is causing the slippage can be found by testing in another selector lever position.
6. When stall test speeds are low and the engine is properly tuned, converter stator clutch problems are indicated. A road test must be performed to determine the exact cause of the trouble.
7. If the stall test speeds are 300 to 400 RPM below the speeds shown in the above table, and the car cruises properly but has very poor acceleration, the stator clutch is slipping.
8. If the stall test speeds are 300 to 400 RPM below specifications, and the car drags at cruising speeds and has poor acceleration, the stator clutch is installed backwards.
9. When the stall test speeds show normal speeds and the acceleration is good, but the car drags at cruising speeds, the difficulty is due to a seized stator. If the stator is defective, replace the converter.