Chrysler Town, Dodge Caravan. Manual - part 420
OIL PUMP
DESCRIPTION
The oil pump is located in the pump housing inside
the bell housing of the transaxle case (Fig. 283). The
oil pump consists of an inner and outer gear, a hous-
ing, 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,
the
clearance
between
the
gear
teeth
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.
DISASSEMBLY
When disassembling the transaxle it is necessary
to inspect the oil pump for wear and damage.
(1) Remove the reaction shaft support bolts.
(2) Remove reaction shaft support from pump
housing (Fig. 284).
(3) Remove the pump gears (Fig. 285) and check
for wear and damage on pump housing and gears.
(4) Re-install the gears and check clearances.
(5) Measure the clearance between the outer gear
and the pump pocket (Fig. 286). Clearance should be
0.089–0.202 mm (0.0035-0.0079 in.).
(6) Measure clearance between outer gear and
crescent.
Clearance
should
be
0.060-0.298
mm
(0.0023-0.0117 in.).
(7) Measure clearance between inner gear and
crescent.
Clearance
should
be
0.093-0.385
mm
(0.0036-0.0151 in.).
(8) Position an appropriate piece of Plastigage
across both pump gears.
Fig. 282 Overdrive/Underdrive Shafts
1 - OVERDRIVE SHAFT
2 - #3 THRUST PLATE (3 TABS)
3 - #3 THRUST WASHER (5 TABS)
4 - UNDERDRIVE SHAFT
5 - #2 NEEDLE BEARING (3 TABS)
6 - INPUT CLUTCH ASSEMBLY
21 - 230
41TE AUTOMATIC TRANSAXLE
RS
INPUT CLUTCH ASSEMBLY (Continued)