Torque Converter Clutch Diagnosis

The torque converter stator assembly and its related roller clutch can have one of two different type malfunctions. The stator assembly freewheels in both directions or it remains locked up at all times.

If the stator roller clutch becomes ineffective, the stator assembly will freewheel in both directions at all times. With this condition, the vehicle will tend to have poor acceleration from a standstill. At speeds above 30-35 mph, the vehicle may act normally. If poor acceleration problems are encountered, it must first be determined that the vehicles exhaust system is not restricted, the engine is properly tuned and the transaxle is starting out in first gear, before the converter is determined to be the source of the problem. Driving the vehicle in reverse and checking for poor performance will help determine if stator is freewheeling at all times.

If the stator assembly remains locked up at all times, the engine and vehicle speed will tend to be limited or restricted at high speeds. The vehicles performance will be normal when accelerating from a standstill. Engine overheating may be noted, and a visual inspection of the converter may show a blue color from the overheating that will occur.

Under the above conditions, if the converter has been removed from the transaxle, the stator clutch can be checked by inserting a finger into the splined inner race of the roller clutch and trying to turn the race in both directions. The inner race should turn freely in the clockwise direction, but not turn or be difficult to turn in the counterclockwise direction. Do not use the pump cover or stator shaft to turn the race, as the results may be misleading.