Dodge RAM 1500 1998 Owner's Manual page 2015

21 - 312 AUTOMATIC TRANSMISSION - 45RFE/545RFE
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 391
OUTPUT SPEED SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 391
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 391
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 392
TOW/HAUL OVERDRIVE SWITCH
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 392
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 392
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 393
PISTONS
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 393
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 393
PLANETARY GEARTRAIN
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 395
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 396
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 396
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 396
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 397
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
SHIFT MECHANISM
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 398
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 398
SOLENOID SWITCH VALVE
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 398
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 398
SOLENOIDS
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 398
AUTOMATIC TRANSMISSION -
45RFE/545RFE
DESCRIPTION
The 45RFE/545RFE automatic transmissions is a
sophisticated, multi-range, electronically controlled
transmission which combines optimized gear ratios
for responsive performance, state of the art efficiency
features and low NVH. Other features include driver
adaptive shifting and three planetary gear sets to
provide wide ratio capability with precise ratio steps
for optimum driveability. The three planetary gear
sets also make available a unique alternate second
gear ratio. The primary 2nd gear ratio fits between
1st and 3rd gears for normal through-gear accelera-
tions. The alternate second gear ratio (2prime) allows
smoother 4-2 kickdowns at high speeds to provide
2nd gear passing performance over a wider highway
cruising range.
The hydraulic portion of the transmission consists
of the transmission fluid, fluid passages, hydraulic
valves, and various line pressure control components.
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 399
TORQUE CONVERTER
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 399
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 403
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 404
TRANSMISSION CONTROL RELAY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 405
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 405
TRANSMISSION RANGE SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 405
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 405
TRANSMISSION SOLENOID/TRS ASSEMBLY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 406
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 406
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 408
TRANSMISSION TEMPERATURE SENSOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 408
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 408
VALVE BODY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . 408
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . 408
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 410
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . 413
ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . 414
The primary mechanical components of the trans-
mission consist of the following:
• Three multiple disc input clutches
• Three multiple disc holding clutches
• Five hydraulic accumulators
• Three planetary gear sets
• Dual Stage Hydraulic oil pump
• Valve body
• Solenoid pack
The TCM is the "heart" or "brain" of the electronic
control system and relies on information from vari-
ous direct and indirect inputs (sensors, switches, etc.)
to determine driver demand and vehicle operating
conditions. With this information, the TCM can cal-
culate and perform timely and quality shifts through
various output or control devices (solenoid pack,
transmission control relay, etc.).
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