Component List - TorqShift(R)6
Component List
Cutaway View
Major Components
This transmission has the following major components:
- Transmission case with integral torque converter housing
- Torque converter
- Fluid pump
- Three drive clutches:
- Forward (1,2,3,4) clutch
- Direct (3,5,R) clutch
- Overdrive (4,5,6) clutch
- Three brake clutches:
- Intermediate (2,6) clutch
- Low/reverse (1,R) clutch
- Low/One-Way Clutch (OWC)
- Two planetary gearsets:
- Front single planetary gearset (1 sun gear, 1 carrier, 1 ring gear)
- Rear ravigneaux planetary gearset (2 sun gears, 1 carrier with 2 sets of pinion gears and 1 ring gear)
- Main control:
- Upper valve body
- Lower valve body
- Five shift solenoids, Line Pressure Control (LPC) solenoid and Torque Converter Clutch (TCC) solenoid
All gear shifts from 1st to 6th or from 6th to 1st are power-on overlapping shifts. That is, during the shift, one of the clutches must continue to transmit the drive at lower main pressure until the other clutch is able to accept the input torque.
The shift elements, clutches or brakes are engaged hydraulically. The transmission fluid pressure builds up between the cylinder and the piston, pressing the clutches together.
The purpose of the shift elements is to carry out in-load shifts with no interruption to traction.
Multi-plate clutches; forward, direct and overdrive, supply power from the engine to the planetary geartrain. Multi-disc brakes, intermediate and low/reverse hold components of the the planetary geartrain to the transmission housing to achieve a torque reaction effect.
Multi-Plate Clutch
Clutches; overdrive (4,5,6), forward (1,2,3,4) and direct (3,5,R) are balanced in terms of dynamic pressure. That is, their pistons are exposed to the transmission fluid flow on both sides to prevent pressure buildup in the clutch as speed increases. This dynamic pressure equalization process is achieved by a baffle plate and pressure-free transmission fluid supply by a lubricating passage, through which the space between the piston and baffle plate is filled with transmission fluid.
The advantages of this dynamic pressure equalization are:
- reliable clutch engagement and release in all speed ranges.
- improved shift refinement.
Shift Overlap Control
The electro-hydraulic shift action is obtained by means of various valves including pressure regulators in the main control valve body controlled by the PCM or Transmission Control Module (TCM). They engage or disengage the relevant clutches or brakes at the correct moments.
Hydraulic Systems
Fluid Pump
The torque converter is supported in the pump by a needle roller bearing. The pump is driven directly from the engine by the torque converter and supplies hydraulic fluid to the transmission and the hydraulic control system.
The fluid pump draws transmission fluid in through the transmission fluid filter from the sump and delivers it at high pressure to the main pressure valve in the main control valve body unit. The main pressure valve adjusts the pressure and returns excess transmission fluid to the transmission fluid sump.
Fluid Filter
All transmission fluid that is picked up from the transmission fluid pan passes through the transmission fluid filter. The transmission fluid filter and its accompanying seal are part of the fluid path from the pan to the pump.
Front Single Planetary Gearset
The front single planetary gear overdrive carrier is driven by the input shaft. The single planetary gearset consists of the following components:
- One (No. 1) sun gear
- Four planetary gears meshing with the sun gear
- One planetary carrier
- One ring gear
Rear Ravigneaux Planetary Gearset
The rear ravigneaux planetary gearset consists of the following components:
- Two sun gears of different sizes
- Three long planetary gear pinions meshing with the No. 2 sun gear and the ring gear
- Three short planetary gear pinions meshing with the No. 3 sun gear and the long pinions
- One planetary carrier
- One ring gear
Output Shaft
The output shaft provides torque to the driveshaft and rear axle assembly. It is driven by the ring gear of the rear planetary gearset.