Hydraulic System

Fluid Pump
The front pump support and gear provides the volume of fluid required to charge the torque converter, main control valve body, cooling system, lubrication system, and hydraulic apply devices. A variable-capacity, rotor-type pump is used for discharge efficiency and reduced fuel consumption. The front pump support and gear is shaft driven by the torque converter cover.

Filter
All fluid drawn from the transmission fluid pan by the front pump support and gear flows through the filter. If a transmission is to be repaired for a contamination-related failure, always use a new filter and grommet.

Main Control -Valve Body
The main control valve body houses the hydraulic valves and shift solenoid valves. These valves direct fluid flow, restrict fluid flow, and change fluid pressure. The main control valve body receives signals from the solenoid valve body and changes electrical signals into hydraulic actions. The actions control the operation of the hydraulic clutches and the 2-4 band, and supply lubrication to the transmission. The main control valve body consists of four sections: the upper control valve body, main control valve body, premain control valve body, and the lower control valve body. The main control valve body also contains the electronic pressure control solenoid.

Accumulators - 1-2
The 1-2 accumulator reduces shift shock when shifting from first to second gear. The accumulator piston is normally pressed to the right by line pressure. When there is a shift from first to second gear, the 2-4 band engagement pressure pushes the accumulator piston slowly to the left. As a result, the 2-4 band engagement pressure builds up slowly, reducing the shift shock when there is a shift from first to second gear.

Accumulators - 2-3
The 2-3 accumulator reduces shift shock when shifting from second to third gear. The accumulator piston is normally pressed to the left by line pressure. When there is a shift from second to third gear, 3-4 clutch engagement pressure pushes the accumulator piston slowly to the right. As a result, the 3-4 clutch engagement pressure builds up slowly, reducing the shift shock when there is a shift from second to third gear.

Accumulators - N-D
The NEUTRAL-DRIVE (N-D) accumulator moderates a rapid increase in hydraulic pressure during forward clutch engagement. This reduces shift shock when the D range is selected from NEUTRAL. In the NEUTRAL position, line pressure is constantly applied to the right side of the accumulator piston, pushing it to the left. When the D range is selected from NEUTRAL, line pressure which engages the forward clutch is applied to the left side of the N-D accumulator by the manual valve. As a result, the combination of line pressure and spring force overcome the line pressure on the right, moving the accumulator piston gradually to the right. This movement of the piston moderates a rapid increase in line pressure.

Accumulators - N-R
The NEUTRAL-REVERSE (N-R) accumulator reduces shift shock when shifting from NEUTRAL to the REVERSE range (R). The accumulator piston is normally pressed to the left by spring force and line pressure. When there is a shift from NEUTRAL to REVERSE, the accumulator piston is pushed slowly to the right by the reverse clutch pressure. As a result, the reverse clutch pressure builds up slowly, reducing the shift shock when there is a shift to REVERSE.