Oil Pump Description And Operation - Jeep 200 Cherokee Service Manual

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DESCRIPTION AND OPERATION (Continued)
TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston to the impel-
ler's friction material, a total converter engagement
can be obtained. The result of this engagement is a
direct 1:1 mechanical link between the engine and
the transmission.
The engagement and disengagement of the TCC
are automatic and controlled by the Transmission
Control Module (TCM). Inputs that determine clutch
engagement are: coolant temperature, vehicle speed
and throttle position. Clutch engagement is con-
trolled by transmission valve body solenoid number
three and by the converter clutch relay valve. The
solenoid channels line pressure to the clutch through
the relay valve at clutch engagement speeds.
1 – PUMP SEAL
2 – PUMP BODY
3 – STATOR SHAFT
AW–4 AUTOMATIC TRANSMISSION
OIL PUMP
DESCRIPTION
The oil pump (Fig. 13) is located in the pump hous-
ing inside the bell housing of the transmission case.
The oil pump consists of an inner and outer gear, a
housing, and a cover that also serves as the reaction
shaft support.
OPERATION
As the torque converter rotates, the converter hub
rotates the inner and outer gears. As the gears
rotate,
increases in the crescent area, and creates a suction
at the inlet side of the pump. This suction draws
fluid through the pump inlet from the oil pan. As the
clearance between the gear teeth in the crescent area
decreases, it forces pressurized fluid into the pump
outlet and to the valve body.
Fig. 13 Oil Pump Assembly
4 – SEAL RINGS
5 – GEAR
6 – O-RING
the clearance between
21 - 227
the gear teeth