Operation - Dodge Dakota Sport 2001 Service Manual

AN
AUTOMATIC TRANSMISSION - 42RE (Continued)
1 - CONVERTER CLUTCH
2 - TORQUE CONVERTER
3 - OIL PUMP AND REACTION SHAFT SUPPORT ASSEMBLY
4 - FRONT BAND
5 - FRONT CLUTCH
6 - DRIVING SHELL
7 - REAR BAND
8 - TRANSMISSION OVERRUNNING CLUTCH
9 - OVERDRIVE UNIT
10 - PISTON RETAINER
11 - OVERDRIVE CLUTCH
12 - DIRECT CLUTCH
13 - INTERMEDIATE SHAFT
14 - FRONT BEARING
IDENTIFICATION
Transmission identification numbers are stamped
on the left side of the case just above the oil pan gas-
ket surface (Fig. 2). Refer to this information when
ordering replacement parts.
Fig. 2 Transmission Part And Serial Number
1 - PART NUMBER
2 - BUILD DATE
3 - SERIAL NUMBER
GEAR RATIOS The 42RE gear ratios are:
1st . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.74:1
2nd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.54:1
3rd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.00:1
4th . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.69:1
Rev. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.21:1
Location
AUTOMATIC TRANSMISSION - 42RE
15 - HOUSING
16 - REAR BEARING
17 - OUTPUT SHAFT
18 - SEAL
19 - OVERDRIVE OVERRUNNING CLUTCH
20 - OVERDRIVE PLANETARY GEAR
21 - DIRECT CLUTCH SPRING
22 - OVERDRIVE CLUTCH PISTON
23 - VALVE BODY ASSEMBLY
24 - FILTER
25 - FRONT PLANETARY GEAR
26 - REAR CLUTCH
27 - TRANSMISSION
28 - REAR PLANETARY GEAR

OPERATION

The application of each driving or holding compo-
nent is controlled by the valve body based upon the
manual lever position, throttle pressure, and gover-
nor pressure. The governor pressure is a variable
pressure input to the valve body and is one of the
signals that a shift is necessary. First through fourth
gear are obtained by selectively applying and releas-
ing the different clutches and bands. Engine power is
thereby routed to the various planetary gear assem-
blies which combine with the overrunning clutch
assemblies to generate the different gear ratios. The
torque converter clutch is hydraulically applied and
is released when fluid is vented from the hydraulic
circuit by the torque converter control (TCC) solenoid
on the valve body. The torque converter clutch is con-
trolled by the Powertrain Control Module (PCM). The
torque converter clutch engages in fourth gear, and
in third gear under various conditions, such as when
the O/D switch is OFF, when the vehicle is cruising
on a level surface after the vehicle has warmed up.
The torque converter clutch will disengage momen-
tarily when an increase in engine load is sensed by
the PCM, such as when the vehicle begins to go
uphill or the throttle pressure is increased. The
torque converter clutch feature increases fuel econ-
omy and reduces the transmission fluid temperature.
Since the overdrive clutch is applied in fourth gear
only and the direct clutch is applied in all ranges
except fourth gear, the transmission operation for
park, neutral, and first through third gear will be
described first. Once these powerflows are described,
the third to fourth shift sequence will be described.
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