Mechanical Components and Functions

Mechanical Components and Functions

Planetary Gearset
This transaxle has 3 planetary gearsets to provide operation in reverse and 6 forward speeds.

The gearsets are comprised of the following components:
^ Front planetary sun gear (part of the front sun gear and shell assembly)
^ Front planetary carrier
^ Front planetary ring gear
^ Center planetary sun gear
^ Center planetary carrier
^ Center planetary ring gear
^ Rear planetary ring gear
^ Rear planetary carrier
^ Rear planetary sun gear and shell assembly

The front planetary sun gear is splined to the forward (1, 2, 3, 4) clutch and is held stationary in 1st, 2nd, 3rd and 4th gear.

The front planetary carrier is splined to the rear planetary ring gear and transfers power from the rear planetary gearset to the front planetary gearset in 2nd, 3rd, 5th and 6th gear and reverse. The front planetary carrier is splined to the transfer shaft drive gear. The front planetary carrier is the output component for the planetary gearset.

The front planetary ring gear is splined to the center planetary carrier and transfers power from the center planetary gearset to the front planetary gearset in 1st, 2nd, 3rd and 4th gear.

The center planetary sun gear is splined to the input shaft and is used as input to the planetary gearsets in 1st, 2nd, 3rd and 4th gear.

The center planetary ring gear is splined to the rear planetary carrier and transfers power from the center planetary gearset to the rear planetary gearset in 3rd gear, from the rear planetary gearset to the center planetary gearset in 4th gear and is held stationary by the low One-Way Clutch (OWC) and low/reverse clutch in 1st gear and reverse.

The rear planetary carrier is splined to the Overdrive (O/D) (4, 5, 6) clutch hub and transfers power from the input shaft to the rear planetary carrier in 4th, 5th and 6th gear.

The rear planetary sun gear and shell assembly is splined to both the intermediate (2, 6) clutch and the direct (3, 5, R) clutch. The rear planetary sun gear and shell assembly is held stationary by the intermediate (2, 6) clutch in 2nd and 6th gear and is driven by the direct (3, 5, R) clutch in 3rd and 5th gear and reverse.

Planetary Gearset Cutaway View

Planetary Gearset Cutaway View:

Planetary Gearset Exploded View

Planetary Gearset Exploded View (Part 1):

Planetary Gearset Exploded View (Part 2):

Planetary Gearset Exploded View (Part 3):

Input Shaft
The input shaft is part of the direct/O/D clutch assembly and is splined to the torque converter turbine and the center planetary sun gear. The input shaft transfers power from the torque converter to the rear planetary gearset through the direct (3, 5, R) and O/D (4, 5, 6) clutches and the center planetary sun gear.

Input Shaft Cutaway View

Input Shaft Cutaway View:

Input Shaft Exploded View

Input Shaft Cutaway View (Part 1):

Input Shaft Cutaway View (Part 2):

Front Planetary Carrier Hub (Output Hub)
The front planetary carrier hub is splined to the front planetary carrier and the transfer shaft drive gear. This allows torque to be transferred from the planetary gearset to the final drive gearset.

Front Planetary Carrier Hub Cutaway View

Front Planetary Carrier Hub Cutaway View:

Front Planetary Carrier Hub Exploded View

Front Planetary Carrier Hub Exploded View (Part 1):

Front Planetary Carrier Hub Exploded View (Part 2):

Final Drive Gearset
The final drive consists of a gearset that transfers and multiplies torque from the planetary gearsets to the differential.

The final drive consists of the following components:
^ Transfer shaft drive gear
^ Transfer shaft and gear assembly
^ Differential assembly
^ Ring gear

The planetary gear set transfers power to the transfer shaft drive gear through the front planetary carrier hub. The transfer shaft drive gear is part of the stator support assembly. The transfer shaft drive gear turns the transfer shaft and gear assembly which multiplies torque through gear reduction and turns the differential ring gear.

Final Drive Gearset Cutaway View

Final Drive Gearset Cutaway View:

Final Drive Gearset Exploded View

Final Drive Gearset Exploded View (Part 1):

Final Drive Gearset Exploded View (Part 2):

Differential
The differential allows the halfshafts and wheels to rotate at different speeds during cornering and transfers power to the Power Transfer Unit (PTU) for All-Wheel Drive (AWD) vehicles.

The differential assembly consists of the following components:
^ Differential case (part of the final drive carrier)
^ Two pinion gears supported by a pinion shaft
^ Two side gears supported by the differential case and halfshafts

When driving in a straight line, both front wheels rotate at relatively the same speed. This means both side gears are rotating at the same speed, as well, while both pinion gears revolve (but do not rotate) with the side gears. During cornering, the wheel on the outside of the turn is forced to rotate faster than the wheel on the inside of the turn. Since the side gears must now rotate at different speeds, the pinion gears rotate on the pinion shaft allowing the drive axles to rotate at different speeds while still transferring output torque.

Differential

Differential:

Differential Cutaway View

Differential Cutaway View (Part 1):

Differential Cutaway View (Part 2):

Direct (3, 5, R) Clutch
The direct clutch is a drive clutch that transfers power from the direct/O/D hub and shaft assembly to the rear sun gear. The direct clutch is applied in 3rd and 5th gear and reverse.

Hydraulic pressure from the regulator valve in the valve body pushes the direct clutch piston against the direct clutch pack to apply the clutch. The input shaft transfers torque to the rear planetary sun gear as a result of the clutch being applied.

Direct (3, 5, R) Clutch Cutaway View

Direct (3, 5, R) Clutch Cutaway View:

Direct (3, 5, R) Clutch Exploded View

Direct (3, 5, R) Clutch Exploded View (Part 1):

Direct (3, 5, R) Clutch Exploded View (Part 2):

Overdrive (O/D) (4, 5, 6) Clutch
The O/D clutch is a drive clutch that transfers power from the direct/O/D hub and shaft assembly to the rear planetary carrier. The O/D clutch is applied in 4th, 5th and 6th gear.

Hydraulic pressure from the regulator valve in the valve body pushes the O/D clutch piston against the O/D clutch pack to apply the clutch. The input shaft transfers torque to the rear planetary sun gear as a result of the clutch being applied.

Overdrive (O/D) (4, 5, 6) Clutch Cutaway View

Overdrive (O/D) (4, 5, 6) Clutch Cutaway View:

Overdrive (O/D) (4, 5, 6) Clutch Exploded View

Overdrive (O/D) (4, 5, 6) Clutch Exploded View (Part 1):

Overdrive (O/D) (4, 5, 6) Clutch Exploded View (Part 2):

Forward (1, 2, 3, 4) Clutch
The forward clutch is a brake clutch that holds the front sun gear and shell assembly. The forward clutch is applied in 1st, 2nd, 3rd and 4th gear.

Hydraulic pressure from the regulator valve in the valve body pushes the forward clutch piston against the forward clutch pack to apply the clutch. The forward clutch pack is pushed against the low OWC when it is applied. The rear sun gear and shell assembly is held stationary to the transaxle case as a result of the clutch being applied.

Forward (1, 2, 3, 4) Clutch Cutaway View

Forward (1, 2, 3, 4) Clutch Cutaway View:

Forward (1, 2, 3, 4) Clutch Exploded View

Forward (1, 2, 3, 4) Clutch Exploded View (Part 1):

Forward (1, 2, 3, 4) Clutch Exploded View (Part 2):

Low/Reverse Clutch
The low/reverse clutch is a brake clutch that holds the low OWC which is splined to the rear planetary carrier. The low/reverse clutch is applied in manual LOW, REVERSE and 1st gear up to 5 km/h (3 mph).

Hydraulic pressure from the regulator valve, routed through the multiplex shift valve in the valve body, pushes the low/reverse clutch piston against the low/reverse clutch pack to apply the clutch. The rear planetary carrier is held stationary to the transaxle case as a result of the clutch being applied.

Low/Reverse Clutch Cutaway View

Low/Reverse Clutch Cutaway View:

Low/Reverse Clutch Exploded View

Low/Reverse Clutch Exploded View (Part 1):

Low/Reverse Clutch Exploded View (Part 2):

Intermediate (2, 6) Clutch
The intermediate clutch is a brake clutch that holds the rear sun and shell assembly. The intermediate clutch is applied in 2nd and 6th gear.

Hydraulic pressure from the regulator valve in the valve body pushes the intermediate clutch piston against the intermediate clutch pack to apply the clutch. The rear planetary sun gear is held stationary to the transaxle case as a result of the clutch being applied.

Intermediate (2, 6) Clutch Cutaway View

Intermediate (2, 6) Clutch Cutaway View:

Intermediate (2, 6) Clutch Exploded View

Intermediate (2, 6) Clutch Exploded View (Part 1):

Intermediate (2, 6) Clutch Exploded View (Part 2):

Low One-Way Clutch (OWC)
The low OWC is a brake clutch that holds the rear planetary carrier in one direction and allows it to freewheel in the opposite direction which eliminates engine braking in 1st gear when the transaxle is in DRIVE. The low OWC is used in 1st gear when the transaxle is in DRIVE.

Low OWC Cutaway View

Low OWC Cutaway View:

Low OWC Exploded View

Low OWC Exploded View (Part 1):

Low OWC Exploded View (Part 2):

External sealing
The torque converter housing has a lip-type seal that seals the torque converter hub. The manual lever shaft and halfshafts also use lip-type seals. AWD vehicles do not use a RH halfshaft seal, the transaxle is sealed by the PTU on the RH side.

The torque converter housing is sealed to the transaxle case with silicone sealant. The transaxle cover is sealed to the transaxle case with a reusable gasket.

The main control cover is sealed to the transaxle case and the solenoid body with reusable rubber gaskets and the Turbine Shaft Speed (TSS) sensor is sealed to the transaxle cover with an O-ring seal.

The transmission fluid filler tube is sealed to the main control cover with an O-ring seal that is serviced with the transmission fluid filler tube. The transmission fluid level indicator is sealed to the transmission fluid filler tube with an O-ring seal that is serviced with the transmission fluid level indicator.

The line pressure tap plug, transmission fluid drain plug and the lubrication circuit tap plug have pipe threads and seal when tightened to specification.

External Sealing Exploded View

External Sealing Exploded View (Part 1):

External Sealing Exploded View (Part 2):

Bushings, Bearings and Thrust Washer Locations

Bushings, Bearings and Thrust Washer Locations (Part 1):

Bushings, Bearings and Thrust Washer Locations (Part 2):

Bushings, Bearings and Thrust Washer Locations (Part 3):

Lubrication
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 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.

Lubrication Circuits

Lubrication Circuits (Part 1):

Lubrication Circuits (Part 2):

Park
The park gear is located on the transfer shaft and gear assembly. There are lugs around the outer diameter of the park gear to allow the park pawl to hold the park gear stationary to the transaxle case, which holds the differential in place and keeps the vehicle from moving.

When the manual control lever is rotated to the PARK position, the park lock works as follows:
^ The Transmission Range (TR) sensor rotates the range detent plate which pushes the park pawl actuator rod towards the park pawl.
^ The actuator rod pivots the park pawl into the lugs on the park gear, locking the gear stationary to the transaxle case.

Park Component Exploded View