Mechanical System

Component Location

System Operation

System Diagram

Component Description

Planetary Gearset

This transmission has 3 planetary gearsets to provide operation in reverse and 6 forward speeds.

Front planetary gearset consists of the following components:

• Front planetary sun gear
• Front planetary carrier
• Front planetary ring gear

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 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 the output component for the planetary gearset as it is splined to the output hub.

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.

Center planetary gearset consists of the following components:

• Center planetary sun gear
• Center planetary carrier
• Center planetary ring 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, 4th and 5th gear.

The center planetary ring gear is splined to the rear planetary carrier. The center ring gear/rear planetary carrier is held stationary by the low OWC and low-reverse clutch in 1st gear and reverse. The center ring gear/rear planetary carrier is driven by the overdrive (4, 5, 6) clutch in 4th, 5th, and 6th gears.

Rear planetary gearset consists of the following components:

• Rear planetary ring gear
• Rear planetary carrier
• Rear planetary sun gear

The rear planetary carrier is splined to the overdrive (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 is splined to both the intermediate (2, 6) clutch and the direct (3, 5, R) clutch. The rear planetary sun gear 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.

Input Shaft

The input shaft is part of the direct/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 direct (3, 5, R) and overdrive (4, 5, 6) clutches and the center planetary sun gear.

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.

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.

Differential

The differential allows the half shafts and wheels to rotate at different speeds during cornering and transfers power to the PTU for 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 half shafts

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.

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 transmission case as a result of the clutch being applied.

Direct (3, 5, R) Clutch

The direct clutch is a drive clutch that transfers power from the direct/overdrive 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.

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 transmission case as a result of the clutch being applied.

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 8 kmh (5 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 transmission case as a result of the clutch being applied.

Overdrive Clutch

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

Hydraulic pressure from the regulator valve in the valve body pushes the overdrive clutch piston against the overdrive 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.

Low One-Way Clutch

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 transmission is in DRIVE. The low OWC is used in 1st gear when the transmission is in DRIVE.