Stall Speed Test

Special Testing Procedures

Stall Speed 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.

The Stall Speed Test checks:

- Torque Converter Clutch (TCC) operation and installation.
- holding ability of the forward clutch.
- reverse clutch (the low-reverse bands).
- planetary One-Way Clutch (OWC).
- engine driveability concerns.

Conduct this test with the engine coolant and transmission fluid at correct levels and at normal operating temperature.

Apply the parking brake firmly for each Stall Speed Test.

1. Find the specified stall rpm for the vehicle, see the Stall Speed Chart. Use a grease pencil to mark the rpm on the dial of a tachometer.

Stall Speed





2. Connect a scan tool.

3. NOTE: If the rpm recorded by the scan tool exceeds the maximum limits, release the accelerator pedal immediately because clutch or band slippage is indicated.

In each of the following ranges REVERSE, DRIVE and LOW, press the accelerator pedal to the floor and hold it just long enough to let the engine get to Wide Open Throttle (WOT). While making this test, do not hold the throttle open for more than 5 seconds at a time.

4. Note the results in each range.

5. 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 making the next test.

6. Use the stall speed diagnosis chart for corrective actions.

7. NOTE: The stall speed in REVERSE will be lower.

If stall speeds were too high, see the Stall Speed 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 for slippage.

Pressure Diagnostic Chart

Pressure Diagnostic Chart: