Stator One-way Clutch
There are certain things to look for when diagnosing the stator one-way clutch. It is located inside the vehicles torque converter. This part is critical to the operation of the torque converter and overall driveability of the vehicle.
During low speed operation the stator locks creating a vortex. This vortex resultins in torque multiplication. The stator remains locked until the torque converter reaches its coupling phase.
This is a point in the torque converters cycle where the turbine (attached to the transmission) reaches 90% of the impellers (attached to the engine) speed. At this point there is no more torque multiplication and the stator is allowed to spin freely.
If the stators one-way clutch allows the stator to spin freely while at low speeds, there will be a loss of torque multiplication resulting in poor low speed performance. On the other hand if the stators clutch freezes up and remains constantly locked the vehicle will suffer poor high speed performance.
This will result in overheating of the converter and will be evident because the hub will turn dark blue. A little blue discoloration around a torque converters hub is considered normal, but a dark blue is not.
A good way to check for normal operation is to place the converter on a bench and use your fingers to rotate the stator inside of the shell. It will be splined and should spin freely in one direction and should feel lock up in the other. If it spins freely in both directions or if it is locked in both directions the torque converter should be replaced.
