Stall Speed Test
Stall Speed Test
WARNING: Before beginning any service procedure, REFER to Safety Warnings . Failure to follow this instruction may result in serious personal injury.
Component Test
WARNING: Block all wheels, set the parking brake and firmly apply the service brake to reduce the risk of vehicle movement during this procedure. Failure to follow these instructions may result in serious personal injury.
NOTICE: Carry out Line Pressure Test prior to carrying out Stall Speed Test Line Pressure Test. If the line pressure is low at stall, do not carry out Stall Speed Test or further transmission damage will occur.
The Stall Speed Test checks:
- TCC (Torque Converter Clutch) operation and installation.
- holding ability of the forward clutch.
- reverse clutch (the low-reverse bands).
- planetary OWC (One-Way Clutch).
- engine driveability concerns.
Conduct this test with the engine coolant and transmission fluid at correct levels and at normal operating temperature.
Apply the park brake firmly for each Stall Speed Test.
Stall Speed Chart
1. Connect the scan tool.
2. NOTE: If the recorded rpm exceeds the maximum limit, release the accelerator pedal immediately because clutch slippage is indicated.
In each of the following ranges Drive, Low and Reverse, press the accelerator pedal to the floor and hold it just long enough to let the engine get to WOT (Wide Open Throttle). While conducting this test, do not hold the throttle open for more than 5 seconds each time.
3. Record the results in each range.
4. After each range, move the selector lever to NEUTRAL and run the engine at 1,000 rpm for about 15 seconds to cool the torque converter before conducting the next test.
5. Use the Stall Speed Diagnosis Chart for corrective actions.
6. NOTE: The stall speed in REVERSE will be lower.
If stall speeds were too high, see the Stall Speed Diagnosis Chart. If stall speeds were too low, first check engine idle speed and tune up. If engine is OK, remove torque converter and check TCC (Torque Converter Clutch) for slippage.