Mechanical Components and Functions: Lubrication: Notes

Transmission fluid enters the lubrication circuits after flowing through the transmission fluid cooler, mounted at the front of the vehicle. When the transmission fluid is not up to operating temperature, a transmission fluid cooler thermal bypass valve, mounted in line of the transmission fluid cooler tubes, allows the transmission fluid to bypass the transmission fluid cooler. Transmission fluid returns to the transaxle from the transmission fluid cooler tubes through the back transmission fluid cooler tube.

The transmission fluid enters 2 main lubrication circuits, the input shaft and final drive lubrication circuits, through the transaxle cover and flows through passages in the transaxle to lubricate the transaxle.

The transmission fluid in the input shaft circuit flows from the back of the input shaft toward the front of the input shaft and passes through ports in the input shaft to lubricate the planetary gearset, clutches, stator support and other components of the transaxle.

The transmission fluid in the final drive lubrication circuit flow from the rear cover to the transfer shaft and lubricates the transfer shaft bearings. The transmission fluid flows through the transfer shaft and feeds both of the differential bearings.

Fig 1: Identifying Thermal Bypass Valve And Transmission Fluid Cooler Return Tube

Courtesy of FORD MOTOR CO.