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.
NOTE:
Carry out Line Pressure Test prior to carrying out Stall Speed Test. If the line pressure is low at stall, do not carry out Stall Speed Test or further transaxle damage will occur.
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.
STALL SPEED CHART
| Engine | Stall Speed |
|---|---|
| 3.5L | 2,350-2,650 |
- Connect the scan tool.
- In each of the following ranges D, L and R, press the accelerator pedal to the floor and hold it just long enough to let the engine get to WOT. While making this test, do not hold the throttle open for more than 5 seconds at a time.
- Note the results in each range.
- 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.
- Use the Stall Speed Diagnosis Chart for corrective actions.
- 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 for slippage.
NOTE:
If the recorded RPM exceeds the maximum limits, release the accelerator pedal immediately because clutch or band slippage is indicated.
NOTE:
The stall speed in REVERSE will be lower.
STALL SPEED DIAGNOSIS CHART
| Range | Possible Source |
|---|---|
| D, L | Forward Clutch Low/Reverse Clutch Low/One-Way Clutch |
| R | Low/Reverse Clutch Direct Clutch |