Oil Pump Description; Operation - Jeep KJ 2005 Service Manual

KJ
OIL PUMP
DESCRIPTION
Fig. 110 Oil Pump
1 - OIL PUMP TO CASE BOLT (6)
2 - OIL PUMP
The oil pump (2) (Fig. 110) is located at the front of
the transmission inside the bell housing and behind
the transmission front cover.
Fig. 111 Oil Pump Gears
1 - PUMP HOUSING
2 - DRIVE GEAR
3 - DRIVEN GEARS
The oil pump consists of two independent pumps.
(Fig. 111)
AUTOMATIC TRANSMISSION - 545RFE
Fig. 112 Oil Pump Valves
1 - TORQUE CONVERTER CLUTCH ACCUMULATOR VALVE
2 - TORQUE CONVERTER CLUTCH CONTROL VALVE
3 - TORQUE CONVERTER CLUTCH SWITCH VALVE
4 - PUMP VALVE BODY
5 - PRESSURE REGULATOR VALVE
6 - TORQUE CONVERTER CLUTCH LIMIT VALVE
The oil pump also contains a number of valves.
The converter clutch switch (3) (Fig. 112) and control
valves (2), pressure regulator valve (5), and converter
pressure limit valve (6) are all located in the oil
pump valve body.
A front seal (2) (Fig. 113), and a bolt on reaction
shaft (5) complete the oil pump assembly.

OPERATION

As the torque converter rotates, the converter hub
rotates the oil pump drive gear. As the drive gear
rotates both driven gears, a vacuum is created when
the gear teeth come out of mesh. This suction draws
fluid through the pump inlet from the oil pan. As the
gear teeth come back into mesh, pressurized fluid is
forced into the pump outlet and to the oil pump
valves.
At low speeds, both sides of the pump supply fluid
to the transmission. As the speed of the torque con-
verter increases, the flow from both sides increases
until the flow from the primary side alone is suffi-
cient to meet system demands. At this point, the
check valve located between the two pumps closes.
The secondary side is shut down and the primary
side supplies all the fluid to the transmission.
CONVERTER CLUTCH SWITCH VALVE
The converter clutch switch valve is used to control
the hydraulic pressure supplied to the front (OFF)
side of the torque converter clutch.
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