Dodge RAM TRUCK 1500 1995 Service Manual page 1383

21 - 100 42RH/46RH/47RH AUTOMATIC TRANSMISSION
TORQUE CONVERTER
A three element torque converter is used for all ap­
plications. The converter consists of the Impeller, sta­
tor and turbine. The converter also contains an
overrunning clutch and a converter clutch mecha­
nism.
A 273 mm (10.75 In.) converter is used with 42RH/
46RH transmissions. A 310 mm (12.2 in.) converter is
used with 47RH transmissions.
The converter modulated clutch consists of a clutch
piston, clutch springs and the clutch disc friction ma­
terial.
The clutch disc Is attached to the converter front
cover. The clutch piston and clutch springs are at­
tached to the turbine hub. The springs dampen en­
gine firing impulses and loads during the initial
phase of converter clutch engagement.
Converter clutch engagement is controlled by the
converter clutch valve and solenoid. Both are located
on the transmission valve body. Clutch engagement
occurs In third gear above 35 mph and in fourth gear
above 50 mph.drive range at speeds above approxi­
mately 30-35 mph.
The converter clutch provides reduced engine
speed, greater fuel economy, and optimum torque
transfer when engaged. Clutch engagement also pro­
vides reduced transmission fluid temperatures.
GEAR RATIOS
42RH forward gear ratios are:
• First gear = 2.74:1
® Second gear = 1.54:1
© Third gear = 1.00:1
© Fourth gear = 0.69:1.
46RH/47RH forward gear ratios are:
o First gear = 2.45:1
• Second gear = 1.45:1
• Third gear = 1.00:1
© Fourth gear = 0.69:1.
RECOMMENDED FLUID
The recommended and preferred fluid for 42RH/
46RH/47RH transmissions is Mopar ATF Plus, type
7176. Dexron II fluid is not really recommended and
should only be used when ATF Plus is not available.
COMPONENTS UNIQUE TO 47RH
Planetary Gears
The transmission and overdrive planetary gear car­
riers in the 47RH are heavy duty components. The
transmission planetary carriers have five pinion
gears. The carrier in the overdrive compounder has
five pinion gears.
Gear Case
The 47RH transmission case is readily identifiable
by the extra reinforcing ribs around the rear servo
area of the case.
The converter housing bolt pattern is unique for
diesel and gas engine versions of the 47RH.
Clutch Packs
Clutch packs used in the V10 and diesel versions
contain the following number of discs and plates:
• front/rear clutch have 4 discs and 3 steel plates
• overdrive clutch has 5 discs and 4 steel plates
• direct clutch has 9 discs and 8 steel plates
Rear Band, Lever and Low-Reverse Drum
The 47RH has a special, extra wide, double wrap
rear band, and a heavy duty band lever and pins.
The double wrap band is positively retained on the
low-reverse drum. A shoulder machined on the for­
ward end of the drum secures the band and main­
tains band location during severe operation. The
band lever screw acts directly against the band. A
strut and second lever is not used.
Low-Reverse Drum And Overdrive piston retainer
The low-reverse drum and overdrive piston re­
tainer were changed during mid-1994 production.
The front face of the hub bore in the low-reverse
drum has been counterbored for a thrust washer. The
washer has two locating tabs which fit in matching
slots in the overdrive piston retainer hub. The new
retainer, drum, and thrust washer can be used in
previous 47RH models and will be the only parts
supplied for service.
Governor Weight Assembly
Two governor weight assemblies are used. A 2-stage
weight is used in diesel models and a 3-stage weight
is used in V10 models. The diesel governor inner and
outer weights are made of a solid brass/bronze alloy.
The V10 weight assembly has a brass/bronze inner
and intermediate weight but uses an aluminum outer
weight.
The heavier diesel weight assembly provides the
shift points needed to offset lower operating speeds of
a diesel engine. Do not interchange weight assem­
blies a shift points will be incorrect.
The governor body bolts at the governor valve side
of the body are longer to accommodate a counter­
weight on each bolt. The counterweights offset the
heavier weight assembly used in 47RH models.
TEMPERATURE SENSOR AND INDICATOR LAMP
Overdrive clutch and converter clutch operation is
also controlled by a temperature sensor. The sensor
is located in a transmission fluid cooler line (Fig. 3).