Dodge Durango (DN). Manual — part 74
DESCRIPTION AND OPERATION
46RE TRANSMISSION
DESCRIPTION
The 46RE (Fig. 1) is a four speed fully automatic
transmissions with an electronic governor. The 46RE
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 46RE transmission is cooled by an integral
fluid cooler inside the radiator.
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46RE AUTOMATIC TRANSMISSION
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Fig.
1
46RE
T
ransmission
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46RE AUTOMATIC TRANSMISSION
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DESCRIPTION AND OPERATION (Continued)
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.
GEAR RATIOS
The 46RE gear ratios are:
• 1st 2.45:1
• 2nd 1.45:1
• 3rd 1.00:1
• 4th 0.69:1
• Rev. 2.21
OPERATION
The application of each driving or holding compo-
nent is controlled by the valve body based upon the
manual lever position and governor 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
releasing
the
different
clutches and bands. Engine power is thereby routed
to the various planetary gear assemblies which com-
bine with the overrunning clutch assemblies to gen-
erate 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 controlled by the
Powertrain Control Module (PCM). The torque con-
verter clutch engages in fourth gear, and in third
gear when the O/D switch is OFF, when the vehicle
is cruising on a level plane after the vehicle has
warmed up. The torque converter clutch will disen-
gage momentarily 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.
1 – TORQUE CONVERTER
2 – INPUT SHAFT
3 – OIL PUMP
4 – FRONT BAND
5 – FRONT CLUTCH
6 – REAR CLUTCH
7 – PLANETARIES
8 – REAR BAND
9 – OVERRUNNING CLUTCH
10 – OVERDRIVE CLUTCH
11 – DIRECT CLUTCH
12 – PLANETARY GEAR
13 – OUTPUT SHAFT
14 – SEAL
15 – INTERMEDIATE SHAFT
16 – OVERDRIVE OVERRUNNING CLUTCH
17 – DIRECT CLUTCH SPRING
18 – OVERDRIVE PISTON RETAINER
19 – FILTER
20 – VALVE BODY
Fig. 2 Transmission Part And Serial Number
Location
1 – PART NUMBER
2 – BUILD DATE
3 – SERIAL NUMBER
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46RE AUTOMATIC TRANSMISSION
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DESCRIPTION AND OPERATION (Continued)
PARK POWERFLOW
As the engine is running and the crankshaft is
rotating, the flexplate and torque converter, which
are also bolted to it, are all rotating in a clockwise
direction as viewed from the front of the engine. The
notched hub of the torque converter is connected to
the oil pump’s internal gear, supplying the transmis-
sion with oil pressure. As the converter turns, it
turns the input shaft in a clockwise direction. As the
input shaft is rotating, the front clutch hub-rear
clutch retainer and all their associated parts are also
rotating, all being directly connected to the input
shaft. The power flow from the engine through the
front-clutch-hub and rear-clutch-retainer stops at the
rear-clutch-retainer. Therefore, no power flow to the
output shaft occurs because no clutches are applied.
The only mechanism in use at this time is the park-
ing sprag (Fig. 3), which locks the parking gear on
the output shaft to the transmission case.
NEUTRAL POWERFLOW
With the gear selector in the neutral position (Fig.
4), the power flow of the transmission is essentially
the same as in the park position. The only opera-
tional difference is that the parking sprag has been
disengaged, unlocking the output shaft from the
transmission case and allowing it to move freely.
Fig. 3 Park Powerflow
1 – LEVER ENGAGED FOR PARK
2 – PARK SPRAG
3 – OUTPUT SHAFT
Fig. 4 Neutral Powerflow
1 – LEVER DISENGAGED FOR NEUTRAL
2 – PARK SPRAG
3 – OUTPUT SHAFT
4 – CAM
5 – LEVER
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46RE AUTOMATIC TRANSMISSION
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DESCRIPTION AND OPERATION (Continued)
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