Jeep Cherokee

 Service Manual

Transmission and transfer case » Automatic transmission-30RH » Description and operation
Accumulator

DESCRIPTION

The accumulator (Fig. 36) is a hydraulic device that has the sole purpose of cushioning the application of a band or clutch. The accumulator consists of a dual-land piston and a spring located in a bore in the transmission case.

OPERATION

Line pressure is directed between the lands of the piston (Fig. 37), bottoming it against the accumulator plate. The accumulator stays in this position after the transmission is placed into a Drive position.

When the 1-2 upshift occurs (Fig. 38), line pressure is directed to the large end of the piston and then to the kickdown servo. As the line pressure reaches the accumulator, the combination of spring pressure and line pressure forces the piston away from the accumulator plate. This causes a balanced pressure situation, which results in a cushioned band application.

After the kickdown servo has become immovable, line pressure will finish pushing the accumulator up into its bore. When the large end of the accumulator piston is seated in its bore, the band or clutch is fully applied.

Fig. 36 Accumulator

1 - ACCUMULATOR PISTON
2 - PISTON SPRING

Fig. 35 Manual Valve

1 - 1-2 GOVERNOR PLUG
2 - 2-3 GOVERNOR PLUG
3 - GOVERNOR REAR CLUTCH ACCUMULATOR
4 - THROTTLE VALVE
5 - LAND #1
6 - PUMP
7 - PRESSURE REGULATOR
8 - LAND #2

NOTE: The accumulator is shown in the inverted position for illustrative purposes.

Fig. 37 Accumulator in Neutral and Drive Positions

Fig. 38 Accumulator in Second Gear Position

1 - BOTTOM IN BORE
2 - SHUTTLE VALVE

30RH automatic transmission

Fluid

Torque converter

Oil pump

Valve body

Accumulator

Pistons

Front clutch

Rear clutch

Overrunning clutch

Planetary gearset

Bands

Servos

Governor

Gearshift mechanism

Converter drainback valve

Brake transmission shift interlock mechanism