Stall Speed Test
WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty, 2018 Ford F-450 Super Duty, 2018 Ford F-350 Super Duty, and 2018 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Carry out the Line Pressure Test prior to the Stall Speed Test. If line pressure is low, do not carry out the stall test or additional transmission damage will occur. Do not maintain Wide Open Throttle (WOT) in any gear range for more than 5 seconds.
NOTE:
After testing each of the ranges, move the selector lever into the NEUTRAL position and run the engine at 1, 000 rpm for about 15 seconds to allow the torque converter to cool off before continuing onto the next range.
NOTE:
If the engine speed exceeds maximum specified rpm, release the accelerator pedal immediately.
NOTE:
Only perform the stall speed test with the engine and transmission at normal operating temperatures.
The Stall Speed Test checks the operation of the following items:
- Torque converter reactor One-Way Clutch (OWC)
- Forward clutch
- Low/reverse clutch
- Direct clutch
- Engine driveability concerns
- Connect a scan tool.
- Press the accelerator pedal to WOT in each range. Record the rpm reached in each range. Stall speeds should be in the appropriate range.
Stall Speed
| Engine | Drive | Reverse |
|---|---|---|
| Diesel | 1, 600-1, 750 rpm | 1, 800-2, 000 rpm |
| Gas | 2, 100-2, 300 rpm 1, 900-2, 200 rpm | 1, 900-2, 200 rpm |
Stall Speed Diagnosis Chart
| Test Results | Possible Source |
|---|---|
| Stall speed high - R only | General line pressure concerns Direct (3, 5, R) clutch Low Reverse (1, R) clutch |
| Stall speed high - (D) | General line pressure concerns Forward (1, 2, 3, 4) clutch Low/Reverse OWC |
| Stall speed low - (D), 3, 2, 1 and R | Torque converter reactor OWC Engine driveability concerns |