FRONT SERVO PISTON . . . . . . . . . . . . . . . . . . 122
REAR SERVO PISTON. . . . . . . . . . . . . . . . . . . . 122
OIL PUMP AND REACTION SHAFT SUPPORT. . 123
FRONT CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . 127
REAR CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . 129
PLANETARY GEARTRAIN/OUTPUT SHAFT . . . . 132
OVERDRIVE UNIT . . . . . . . . . . . . . . . . . . . . . . . 137
CLEANING AND INSPECTION
VALVE BODY . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
TRANSMISSION. . . . . . . . . . . . . . . . . . . . . . . . . 155
OVERRUNNING CLUTCH/LOW-REVERSE
DRUM/OVERDRIVE PISTON RETAINER . . . . . 156
ACCUMULATOR. . . . . . . . . . . . . . . . . . . . . . . . . 156
FRONT SERVO . . . . . . . . . . . . . . . . . . . . . . . . . 156
REAR SERVO . . . . . . . . . . . . . . . . . . . . . . . . . . 156
OIL PUMP AND REACTION SHAFT SUPPORT. . 156
FRONT CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . 157
REAR CLUTCH . . . . . . . . . . . . . . . . . . . . . . . . . 158
PLANETARY GEARTRAIN . . . . . . . . . . . . . . . . . 158
OVERDRIVE UNIT . . . . . . . . . . . . . . . . . . . . . . . 158
ADJUSTMENTS
BRAKE TRANSMISSION SHIFT INTERLOCK . . . 159
TRANSMISSION THROTTLE VALVE CABLE
ADJUSTMENT. . . . . . . . . . . . . . . . . . . . . . . . . 159
GEARSHIFT CABLE . . . . . . . . . . . . . . . . . . . . . . 161
BAND ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . 162
VALVE BODY . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
SCHEMATICS AND DIAGRAMS
HYDRAULIC SCHEMATICS . . . . . . . . . . . . . . . . 164
SPECIFICATIONS
TRANSMISSION. . . . . . . . . . . . . . . . . . . . . . . . . 176
SPECIAL TOOLS
RE TRANSMISSIONS . . . . . . . . . . . . . . . . . . . . . 177
DESCRIPTION AND OPERATION
42RE AUTOMATIC TRANSMISSION
DESCRIPTION
The 42RE is a four speed fully automatic transmis-
sion (Fig. 1) with an electronic governor. The 42RE is
equipped with a lock-up clutch in the torque con-
verter. First through third gear ranges are provided
by the clutches, bands, overrunning clutch, and plan-
etary gear sets in the transmission. Fourth gear
range is provided by the overdrive unit that contains
an overdrive clutch, direct clutch, planetary gear set,
and overrunning clutch.
The transmission contains a front, rear, and direct
clutch which function as the input driving compo-
nents. They also contain the kickdown (front) and the
low/reverse (rear) bands which, along with the over-
running clutch and overdrive clutch, serve as the
holding components. The driving and holding compo-
nents combine to select the necessary planetary gear
components, in the front, rear, or overdrive planetary
gear set, transfer the engine power from the input
shaft through to the output shaft.
The valve body is mounted to the lower side of the
transmission and contains the valves to control pres-
sure regulation, fluid flow control, and clutch/band
application. The oil pump is mounted at the front of
the transmission and is driven by the torque con-
verter hub. The pump supplies the oil pressure nec-
essary for clutch/band actuation and transmission
lubrication.
The 42RE transmission is cooled by an integral
fluid cooler inside the radiator.
21 - 2
42RE AUTOMATIC TRANSMISSION
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