•  The 5R55S transmission provides lubrication for rotating mechanical components through three hydraulic circuits to the front, center and rear areas. Fluid in the torque converter hydraulic circuit provides fluid to lubricate the impeller hub bushing.

•  Fluid in this circuit also flows from the transmission case, through a tube, to a cooler located at the front of the vehicle. Fluid from the cooler returns through another tube into the transmission and then through the three lube circuits.

•  When the temperature of fluid that exits the torque converter contains less heat, the action of a thermostatically controlled valve in the main control causes the cooler to be bypassed. Fluid flows directly from the torque converter into the lube circuits.

•  As transmission fluid temperature increases, the thermostatically controlled valve allows directs the flow of fluid exiting the torque converter to pass through the cooler before it enters the lube circuits.