Stall Speed Test

Stall Speed Test

The stall speed test checks:

- Torque converter clutch operation and installation
- Holding ability of the forward clutch
- Reverse clutch (the low-reverse bands)
- Planetary one-way clutch
- Engine performance

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

Apply the service and parking brake control (2780) firmly for each stall speed test.

Stall Speed Chart:

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

2. Connect tachometer to engine.

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

3. In each of the following ranges: D, 2, 1, R, 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 five 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 1OOO rpm for about 15 seconds to cool the torque converter (7902) before making the next test.

Stall Speed Diagnosis Chart:

6. Refer to the Stall Speed Diagnosis chart for corrective actions.