Apply Components
Apply ComponentsShift Elements
NOTE: All friction and steel clutch plates use a wave designed plate.
In addition to the torque converter, the other shift elements are:
^ three rotating multi-plate clutches: forward, direct and overdrive.
^ two fixed multi-disc brakes: intermediate and low/reverse.
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 these 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, press against the transmission housing in order to achieve a torque reaction effect.
Multi-Plate Clutch
Clutches; overdrive, forward and direct are balanced in terms of dynamic pressure. That is, their pistons are exposed to the transmission fluid flow on both sides, in order to prevent pressure buildup in the clutch as speed increases. This equalization process is achieved by a baffle plate and pressure-free transmission fluid supply by a lubricating passage, through which the space between 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 in the transmission control module (TCM) and main control valve body, actuated by pressure regulators. They engage or disengage the relevant clutches or brakes at the correct moments.