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 gears.
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 gears and reverse. The front planetary carrier is splined to the drive chain drive sprocket. 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 gears.
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 gears.
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 gears and reverse.
Planetary Gearset Cutaway View
Planetary Gearset Exploded View
Input Shaft
The input shaft is part of the direct/O/D (Overdrive) 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 center planetary sun gear and the direct (3, 5, R) and O/D (Overdrive) (4, 5, 6) clutches.
Input Shaft Cutaway View
Input Shaft Exploded View
Front Planetary Carrier Hub (Output Hub)
The front planetary carrier hub/park gear is splined to the front planetary carrier and the drive chain drive sprocket. 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 Exploded View
Final Drive Chain, Sprockets and Planetary Gearset
The final drive consists of a drive chain and sprockets and a planetary gearset and differential assembly. The drive chain and sprockets transfer torque from the front planetary carrier hub to the differential assembly that has a planetary gearset integrated into it for final drive torque multiplication.
The final drive consists of the following components:
- Drive sprocket
- Drive chain
- Driven sprocket
- Final drive sun gear
- Final drive ring gear
- Final drive planetary carrier and differential assembly
Final Drive Component Cutaway View
Final Drive Component Exploded View
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 Cutaway View
Differential Exploded View
Direct (3, 5, R) Clutch
The direct clutch is a drive clutch that transfers power from the direct/O/D (Overdrive) clutch hub assembly to the rear planetary sun gear and shell assembly. The direct clutch is applied in 3rd and 5th gears 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 and direct/O/D (Overdrive) clutch hub assembly transfers torque to the rear planetary sun gear and shell assembly as a result of the clutch being applied.
Direct (3, 5, R) Clutch Cutaway View
Direct (3, 5, R) Clutch Exploded View
Overdrive (O/D) (4, 5, 6) Clutch
The O/D (Overdrive) clutch is a drive clutch that transfers power from the direct/O/D (Overdrive) clutch hub assembly to the rear planetary carrier. The O/D (Overdrive) clutch is applied in 4th, 5th and 6th gears.
Hydraulic pressure from the regulator valve in the valve body pushes the O/D (Overdrive) clutch piston against the O/D (Overdrive) clutch pack to apply the clutch. The input shaft and direct/O/D (Overdrive) clutch hub assembly transfers torque to the rear planetary carrier as a result of the clutch being applied.
Overdrive (O/D) (4, 5, 6) Clutch Cutaway View
Overdrive (O/D) (4, 5, 6) Clutch Exploded View
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 gears.
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 front 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 Exploded View
Low/Reverse Clutch
The low/reverse clutch is a brake clutch that holds the low OWC (One-Way Clutch) which is splined to the rear planetary carrier. The low/reverse clutch is applied in manual LOW, REVERSE and 1st gear up to 8 km/h (5 mph).
Hydraulic pressure from the regulator 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 Exploded View
Intermediate (2, 6) Clutch
The intermediate clutch is a brake clutch that holds the rear planetary sun gear and shell assembly. The intermediate clutch is applied in 2nd and 6th gears.
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 low OWC (One-Way Clutch) works as a pressure plate for the intermediate (2, 6) clutch. The rear planetary sun gear and shell assembly 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 Exploded View
Low One-Way Clutch (OWC)
The low OWC (One-Way Clutch) 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 (One-Way Clutch) is also the pressure plate for the intermediate (2, 6) clutch.
Low One-Way Clutch (OWC) Cutaway View
Low One-Way Clutch (OWC) Exploded View
External Sealing
The torque converter housing has a lip-type seal that seals the torque converter hub. The pump assembly seals to the torque converter housing with a rubber seal. The manual shaft and halfshafts also use lip-type seals. All-Wheel Drive (AWD) vehicles do not use a RH halfshaft seal, the transaxle is sealed by the Power Transfer Unit (PTU) on the RH side.
The torque converter housing is sealed to the transaxle case with silicone sealant.
The main control cover is sealed to the transaxle case with silicone sealant and seals to the solenoid body with a reusable rubber gasket. The Turbine Shaft Speed (TSS) sensor is sealed to the transaxle case with an O-ring seal.
The line pressure tap plug and transmission fluid drain plug have pipe threads and seal when tightened to specification.
The transmission fluid filler tube is sealed to the torque converter housing with an O-ring seal.
External Sealing Exploded View
Bearing and Thrust Washer Locations
The No. 4 thrust bearing is part of the rear planetary carrier assembly. The No. 9 thrust bearing is part of the front planetary carrier assembly. The No. 14 thrust bearing is part of the differential assembly.
Lubrication
Transmission fluid enters the lubrication circuits after flowing through the transmission fluid cooler. The transmission fluid cooler is mounted at the front of the vehicle. When the transmission fluid is not up to operating temperature, an internal thermal bypass valve allows the transmission fluid to bypass the transmission fluid cooler. When the transmission fluid circulates through the transmission fluid cooler, the transmission fluid returns to the transaxle from the transmission fluid cooler tubes through the back transmission fluid cooler tube.
The transmission fluid enters main lubrication circuit through the transaxle case and flows through passages in the input shaft 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, final drive assembly and other components of the transaxle.
Lubrication Passages
Park
The park gear is splined to the front planetary carrier and the drive chain drive sprocket. 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 final drive assembly 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
