Dodge Durango (DN). Manual — part 37

TORQUE CONVERTER CLUTCH (TCC)

In a standard torque converter, the impeller and

turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine’s piston to the front
cover’s friction material, a total converter engage-
ment can be obtained. The result of this engagement
is a direct 1:1 mechanical link between the engine
and the transmission.

Converter clutch engagement in third or fourth gear

range is controlled by sensor inputs to the powertrain
control module. Inputs that determine clutch engage-
ment are: coolant temperature, engine rpm, vehicle
speed, throttle position, and manifold vacuum. The
torque converter clutch is engaged by the clutch sole-
noid on the valve body. The clutch can be engaged in
third and fourth gear ranges depending on overdrive
control switch position. If the overdrive control switch is
in the normal ON position, the clutch will engage after
the shift to fourth gear, and above approximately 72
km/h (45 mph). If the control switch is in the OFF posi-
tion, the clutch will engage after the shift to third gear,
at approximately 56 km/h (35 mph) at light throttle.

OIL PUMP

DESCRIPTION

The oil pump (Fig. 17) is located in the pump hous-

ing inside the bell housing of the transmission case.
The oil pump consists of an inner and outer gear, a
housing, 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.

VALVE BODY

DESCRIPTION

The valve body consists of a cast aluminum valve

body, a separator plate, and transfer plate. The valve
body contains valves and check balls that control
fluid delivery to the torque converter clutch, bands,
and frictional clutches. The valve body contains the

following components (Fig. 18), (Fig. 19), (Fig. 20),
and (Fig. 21):

• Regulator valve

• Regulator valve throttle pressure plug

• Line pressure plug and sleeve

• Kickdown valve

• Kickdown limit valve

• 1–2 shift valve

• 1–2 control valve

• 2–3 shift valve

• 2–3 governor plug

• 3–4 shift valve

• 3–4 timing valve

• 3–4 quick fill valve

• 3–4 accumulator

• Throttle valve

• Throttle pressure plug

• Switch valve

• Manual valve

• Converter clutch lock-up valve

• Converter clutch lock-up timing Valve

• Shuttle valve

• Shuttle valve throttle plug

• Boost Valve

• 10 check balls
By adjusting the spring pressure acting on the reg-

ulator valve, transmission line pressure can be
adjusted.

Fig. 17 Oil Pump Assembly

1 – OIL SEAL
2 – OIL PUMP BODY
3 – VENT
4 – REACTION SHAFT SUPPORT
5 – INNER ROTOR
6 – OUTER ROTOR
7 – “O” RING

21 - 14

42/44RE AUTOMATIC TRANSMISSION

DN

DESCRIPTION AND OPERATION (Continued)

Fig. 18 Upper Housing Control Valve Locations

1 – UPPER HOUSING
2 – REGULATOR VALVE
3 – SWITCH VALVE
4 – REGULATOR VALVE SPRING
5 – KICKDOWN VALVE
6 – KICKDOWN DETENT
7 – THROTTLE VALVE AND SPRING

8 – MANUAL VALVE
9 – 1–2 GOVERNOR PLUG
10 – GOVERNOR PLUG COVER
11 – THROTTLE PLUG
12 – 2–3 GOVERNOR PLUG
13 – SHUTTLE VALVE PRIMARY SPRING

DN

42/44RE AUTOMATIC TRANSMISSION

21 - 15

DESCRIPTION AND OPERATION (Continued)

Fig. 19 Shuttle and Boost Valve Locations

1 – SPRING
2 – RETAINER
3 – BOOST VALVE
4 – BOOST VALVE PLUG
5 – SPRING GUIDES
6 – E-CLIP
7 – SHUTTLE VALVE SECONDARY SPRING

8 – SHUTTLE VALVE COVER
9 – SHUTTLE VALVE
10 – SHUTTLE VALVE PRIMARY SPRING
11 – GOVERNOR PLUG COVER
12 – THROTTLE PLUG
13 – UPPER HOUSING
14 – BOOST VALVE COVER

21 - 16

42/44RE AUTOMATIC TRANSMISSION

DN

DESCRIPTION AND OPERATION (Continued)

Fig. 20 Upper Housing Shift Valve and Pressure Plug Locations

1 – UPPER HOUSING
2 – 1–2 SHIFT VALVE AND SPRING
3 – 2–3 SHIFT VALVE AND SPRING
4 – 2–3 THROTTLE PLUG
5 – LIMIT VALVE HOUSING
6 – LIMIT VALVE COVER
7 – LIMIT VALVE AND SPRING

8 – RETAINER
9 – 1–2 SHIFT CONTROL VALVE AND SPRING
10 – PRESSURE PLUG COVER
11 – LINE PRESSURE PLUG
12 – PLUG SLEEVE
13 – THROTTLE PRESSURE SPRING AND PLUG

DN

42/44RE AUTOMATIC TRANSMISSION

21 - 17

DESCRIPTION AND OPERATION (Continued)