Converter Transmission’s Stall Speed:
The stall speed is the engine speed (rpm) obtained at full throttle when the converter output shaft is locked.
NOTE: It is possible that the vehicle brakes will not hold an electronically controlled transmission.
Do not exceed 120°C [248°F] converter oil temperature. Overheating can result and converter damage can occur. If the oil temperature exceeds 120°C [248°F], put the transmission in neutral, and operate the engine until the oil temperature is below 120°C [248°F]. Check the converter oil level.
The following equipment is needed for this check:
• Stopwatch
• Equipment manufacturer’s stall speed and time-to-stall specifications.
Place the gear selector in the highest gear or full forward.
Make sure the vehicle has good brakes and air pressure in the brake system.
NOTE: The brakes must prevent the vehicle from moving when the engine is at full throttle. Engage the vehicle
brakes to keep the vehicle from moving.
Operate the engine until the converter temperature is 80° C [176°F] or above.
Bring the engine speed back to low idle.
Quickly move the throttle to the full-open position with the vehicle brakes applied.
Check the engine speed (rpm) at the point of stall:
• Always hold the speed until it is stable.
• Take several readings.
• Make sure the readings are accurate.
Check the speed (rpm) against the specifications for the equipment, converter, or automatic transmission.
NOTE: The stall speed for the engine and converter/ transmission can vary ± 8 percent from the manufacturer’s specifications.
If the stall speed is not within the specifications, reference the Stall Speed Checklist in this section.
Check the equipment manufacturer’s troubleshooting procedures for other reasons for stall speed problems.
