Dodge RAM 1500 1998 Owner's Manual page 1916

DR
OIL PUMP
DESCRIPTION
The oil pump (Fig. 109) is located in the pump
housing inside the bell housing of the transmission
case. The oil pump consists of an inner and outer
gear, a housing, and a reaction shaft support.
1 - OIL SEAL
2 - VENT BAFFLE
3 - OIL PUMP BODY
4 - GASKET
5 - REACTION SHAFT SUPPORT
6 - SEAL RINGS
AUTOMATIC TRANSMISSION - 48RE
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. 109 Oil Pump Assembly
7 - BOLTS (6)
8 - #1 THRUST WASHER (SELECTIVE)
9 - INNER GEAR
10 - OUTER GEAR
11 - "O" RING
12 - TORQUE CONVERTER SEAL RING
the clearance between
21 - 213
the gear teeth