Stall Speed Test
WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
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.
CAUTION:
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 transmission damage will occur.
The Stall Speed Test checks the following:
- 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
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.
- Find the specified stall RPM for the vehicle; refer to STALL SPEED Chart.STALL SPEED
Application Min. Max. 4.6L 2V 2,048 2,424 - Connect a scan tool.
- In each of the following ranges R, Overdrive (Circle D), 2, 1 press the accelerator pedal to the floor and hold it just long enough to let the engine get to wide open throttle (WOT). While carrying out 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 shift control 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.
- Refer to the STALL SPEED DIAGNOSIS CHART for corrective actions.
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.
STALL SPEED DIAGNOSIS CHART
| Selector Position | Stall Speeds High | Stall Speeds Low |
|---|---|---|
| Overdrive (Circle D) | Planetary One-Way Clutch (OWC) | |
| Overdrive (Circle D), 2 and 1 | Forward Clutch or Intermediate Clutch | |
| R, Overdrive (Circle D), 2, 1 | Carry Out Pressure Test | Torque Converter Stator OWC or Engine Driveability Concerns |
| R | Reverse Clutch or Low Reverse Band or Servo |