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 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 CHART
   
   

   Engine	Stall Speed
   3.0L (4V)	2,390

2. Connect a tachometer to the 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 R, D and L, press the accelerator pedal to the floor and hold it just long enough to let the engine get to wide open throttle. 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.
NOTE: The stall speed in REVERSE will be lower.
7. 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 torque converter clutch for slippage.
   PRESSURE DIAGNOSTIC CHART
   
   

   Test Results	Possible Source
   Values of both D and R ranges are lower than the standards	Insufficient engine power T/C one-way clutch slipping
   Only the value of D range is higher than the standards	Low line pressure. Shift control solenoid assembly (SLT) failure, primary regulator valve failure Valve body failure (SLC3 hydraulic pressure system) C1 clutch slipping One-way clutch Fl failure
   Only the value of R range is higher than the standards	Low line pressure. Shift control solenoid assembly (SLT) failure, primary regulator valve failure Valve body failure (SLC3 hydraulic pressure system) C3 clutch failure B2 brake failure
   Values of both D and R ranges are higher than the standards	Low line pressure. Shift control solenoid assembly (SLT) failure, primary regulator valve failure Primary regulator valve failure Oil pump failure Oil strainer clogging