SENSOR-TRANSMISSION RANGE
DESCRIPTION
The Transmission Range Sensor (TRS) has 3 primary
functions:
Provide a PARK/NEUTRAL start signal to the
engine controller and the starter relay.
Turn the Back-up lamps on when the transmis-
sion is in REVERSE and the engine (ignition) is
on.
Provide a transmission range signal to the instru-
ment cluster.
The sensor is mounted in the transmission housing
near the valve body, just above the pan rail. It’s in the
same position as the Park/Neutral switch on other
transmissions. The TRS contacts a cammed surface
on the manual valve lever. The cammed surface trans-
lates the rotational motion of the manual lever into the
linear motion of the sensor. The cammed surface on
the manual lever is comprised of two parts controlling
the TRS signal: The insulator portion contacts the
switch poppet when the manual lever is not in PARK
or NEUTRAL. The manual lever itself contacts the
poppet when the lever is in PARK or NEUTRAL; pro-
viding a ground for the signal from the starter relay
and the appropriate engine controller.
OPERATION
As the switch moves through its linear motion contacts
slide across a circuit board which changes the resis-
tance between the range sensing pins of the switch. A
power supply on the instrument cluster provides a reg-
ulated voltage signal to the switch. The return signal is
decoded by the cluster, which then controls the
PRNDL display to correspond with the correct trans-
mission range. A bus message of transmission range
4. Remove timing valve cover.
5. Remove 3-4 timing valve and spring.
6. Remove 3-4 quick fill valve, spring and plug.
7. Remove 3-4 shift valve and spring.
8. Remove converter clutch valve, spring and plug.
9. Remove converter clutch timing valve, retainer and
valve spring.
CLEANING
Clean the valve housings, valves, plugs, springs, and separator plates with a standard parts cleaning solution only.
Do not use gasoline, kerosene, or any type of caustic solution.
Do not immerse any of the electrical components in cleaning solution. Clean the governor solenoid and sensor and
the dual solenoid and harness assembly by wiping them off with dry shop towels only.
Dry all except the electrical parts with compressed air. Make sure all passages are clean and free from obstructions.
Do not use rags or shop towels to dry or wipe off valve body components. Lint from these materials can
stick to valve body parts, interfere with valve operation, and clog filters and fluid passages.
Wipe the governor pressure sensor and solenoid valve with dry, lint free shop towels only. The O-rings on the sen-
sor and solenoid valve are the only serviceable components. Be sure the vent ports in the solenoid valve are open
and not blocked by dirt or debris. Replace the valve and/or sensor only whenDRB scan tool diagnosis indicates this
is necessary. Or, if either part has sustained physical damage (dented, deformed, broken, etc.).
CAUTION: Do not turn the small screw at the end of the solenoid valve for any reason. Turning the screw
in either direction will ruin solenoid calibration and result in solenoidfailure. In addition, the filter on the
solenoid valve is NOT serviceable. Do not try to remove the filter as this will damage the valve housing.
INSPECTION
Inspect the throttle and manual valve levers and shafts. Do not attempt to straighten a bent shaft or correct a loose
lever. Replace these components if worn, bent, loose or damaged in any way.
Inspect all of the valve body mating surfaces for scratches, nicks, burrs,or distortion. Use a straightedge to check
surface flatness. Minor scratches may be removed with crocus cloth using only very light pressure.
Minor distortion of a valve body mating surface may be corrected by smoothing the surface with a sheet of crocus
cloth. Position the crocus cloth on a surface plate, sheet of plate glass orequally flat surface. If distortion is severe
or any surfaces are heavily scored, the valve body will have to be replaced.
CAUTION: Many of the valves and plugs, such as the throttle valve, shuttle valve plug, 1-2 shift valve and
1-2 governor plug, are made of coated aluminum. Aluminum components are identified by the dark color of
thespecialcoatingappliedtothesurface(orbytestingwithamagnet).Donot sand aluminum valves or
plugs under any circumstances. This practice could damage the special coating causing the valves/plugs to
stick and bind.
Inspect the valves and plugs for scratches, burrs, nicks, or scores. Minorsurface scratches on steel valves and
plugs can be removed with crocus cloth butdo not round off the edges of the valve or plug lands.Maintaining
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork shift
rail (2). Minor nicks on the shift rail can be smoothed
with 320-400 grit emery cloth.
Inspect the shift fork wear pads (3, 4). The mode fork
pads are serviceable and can be replaced if neces-
sary. The range fork pads are not serviceable. The
fork must be replaced as an assembly if the pads are
worn or damaged.
Check both of the sleeves for wear or damage, espe-
cially on the interior teeth. Replace the sleeves if wear
or damage is evident.
REAR RETAINER COMPONENTS
Inspect the retainer components. Replace the bearing if rough or noisy. Check the retainer for cracks or wear in the
bearing bore.
Inspect the retaining rings and washers. Replace any part if distorted, bent, or broken. Reuse is not recommended.
Inspect rear extension bushing. Replace if worn or scored.
DRIVE CHAIN
Examine the drive chain and shaft bearings. replace the chain if stretched, distorted, or if any of the links bind.
Replace the bearings if rough, or noisy.
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork shift
rail (2). Minor nicks on the shift rail can be smoothed
with 320-400 grit emery cloth.
Inspect the shift fork wear pads (3). The mode and
range fork pads are serviceable and can be replaced
if necessary.
Check both of the sleeves for wear or damage, espe-
cially on the interior teeth. Replace the sleeves if wear
or damage is evident.
DRIVE CHAIN
Examine the drive chain and shaft bearings. replace the chain if stretched, distorted, or if any of the links bind.
Replace the bearings if rough, or noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear (2) condition carefully. The gear
is only serviced as part of the front case (1). If the
gear is damaged, it will be necessary to replace the
gear and front case as an assembly. Do not attempt to
remove the gear (2)
Inspect the shift fork wear pads (3, 4). The mode (2)
and range (1) fork pads are serviceable and can be
replaced if necessary.
Check both of the sleeves for wear or damage, espe-
cially on the interior teeth. Replace the sleeves if wear
or damage is evident.
REAR EXTENSION HOUSING
Inspect the extension housing seal and bushing. Replace both components if either show any sign of wear or dam-
age.
FRONT OUTPUT SHAFT AND DRIVE CHAIN
Inspect the shaft threads, sprocket teeth, and bearing surfaces. Minor nicksontheteethcanbesmoothedwithan
oilstone. Use 320-400 grit emery to smooth minor scratches on the shaft bearing surfaces. Rough threads on the
shaft can be chased if necessary. Replace the shaft if the threads are damaged, bearing surfaces are scored, or if
any sprocket teeth are cracked or broken.
Examine the drive chain and shaft bearings. Replace the chain and both sprockets if the chain is stretched, dis-
torted, or if any of the links bind. Replace the bearings if rough, or noisy.
LOW RANGE ANNULUS GEAR
Inspect annulus gear (2) condition carefully. The gear
is only serviced as part of the front case (1). If the
gear is damaged, it will be necessary to replace the
gear and front case as an assembly. Do not attempt to
remove the gear.
FRONT AND REAR CASES
Inspect the cases for wear and damage.
Check case condition. If leaks were a problem, look for gouges and severe scoring of case sealing surfaces. Also
make sure the front case mounting studs are in good condition.
Check the front case mounting studs and vent tube. The tube can be secured with Loctite™ 271 or 680 if loose.
Thestudthreadscanbecleanedupwithadieifnecessary.Alsocheckcondition of the fill/drain plug threads in the
rear case. The threads can be repaired with a thread chaser or tap if necessary. Or the threads can be repaired with
Helicoil
stainless steel inserts if required.
MOTOR-SHIFT
DESCRIPTION
The shift motor (1) consists of a permanent magnet
D.C. motor with gear reduction to convert a high
speed-low torque device into a low speed-high torque
device. The output of the device is coupled to a shaft
which internally moves the mode and range forks that
change the transfer case operating ranges. The motor
is rated at 25 amps maximum at (23° C (72° F) with
10 volts at the motor leads.
OPERATION
The transfer case shift motor responds to the Transfer Case Control Module(TCCM) commands to move the trans-
fer case shift sector bi-directionally, as required, to obtain the transfer case operating mode indicated by the instru-
ment panel mounted selector switch.
REMOVAL
NOTE: New shift motor assemblies are shipped in the 2WD/AWD position. If a new shift motor assembly will
be installed, it will be necessary to shift the transfer case to the 2WD/AWDposition prior to motor removal.
1. Raise the vehicle on a suitable hoist.
2. Disengage the wiring connectors from the shift motor and mode sensor.
3. Remove the bolts holding the shift motor and mode sensor assembly onto the transfer case.
4. Separate the shift motor and mode sensor assembly from the transfer case.
INSTALLATION
1. Verify that the shift sector o-ring is clean and properly positioned over the shift sector and against the transfer
case.
NOTE: Verify that the shift motor position and sector shaft orientation are aligned. It may be necessary to
manually shift the transfer case if the shift motor and sector shaft are notaligned.
2. Position the shift motor and mode sensor assembly onto the transfer case.
3. Install the bolts to hold the assembly onto the transfer case. Tighten the bolts to 16-24 Nꞏm (12-18 ft.lbs.).
CAUTION: If the original shift motor and mode sensor assembly bolts are reused, be sure to use Mopar
Lock & Seal or Loctite™ 242 to replenish the lock patch material originallyfound on the bolts
4. Engage the wiring connectors to the shift motor and mode sensor.
5. Refill the transfer case as necessary.
ASSEMBLY-SHIFT MOTOR/MODE SENSOR
DESCRIPTION
The shift motor (1) consists of a permanent magnet
D.C. motor with gear reduction to convert a high
speed-low torque device into a low speed-high torque
device. The output of the device is coupled to a shaft
which internally moves the mode and range forks that
change the transfer case operating ranges. The motor
is rated at 25 amps maximum at (23° C (72° F) with
10 volts at the motor leads.
OPERATION
The transfer case shift motor responds to the Transfer Case Control Module(TCCM) commands to move the trans-
fer case shift sector bi-directionally, as required, to obtain the transfer case operating mode indicated by the instru-
ment panel mounted selector switch.
INPUT GEAR AND PLANETARY CARRIER
Check the teeth on the gear. Minor nicks can be dressed off with an oilstone but replace the gear if any teeth are
broken, cracked, or chipped. The bearing surface on the gear can be smoothed with 300-400 grit emery cloth if
necessary.
Examine the carrier body and pinion gears for wear or damage. The carrier will have to be replaced as an assembly
if the body, pinion pins, or pinion gears are damaged.
Check the lock ring and both thrust washers for wear or cracks. Replace themif necessary. Also replace the lock
retaining ring if bent, distorted, or broken.
SHIFT FORKS/HUBS/SLEEVES
Check condition of the shift forks and mode fork shift rail. Minor nicks on the shift rail can be smoothed with 320-
400 grit emery cloth.
Inspect the shift fork wear pads (3, 4). The mode (2)
and range (1) fork pads are serviceable and can be
replaced if necessary.
Check both of the sleeves for wear or damage, espe-
cially on the interior teeth. Replace the sleeves if wear
or damage is evident.
Input Gear and Carrier Components
1 - PLANETARY CARRIER 4 - CARRIER LOCK RING
2 - REAR THRUST WASHER 5 - CARRIER LOCK RETAINING RING
3 - FRONT THRUST WASHER 6 - INPUT GEAR