torque 48 percent to the front axle and 52 percent to the rear axle along with an electronically controlled clutch pack
that is coupled to the center differential for torque biasing. The NV245 electronics provide an active system because
it can anticipate and prevent slip. The transfer case can redistribute 100 percent of torque to the front or rear axle,
depending on need. For added traction when traversing steep grades, rough terrain or extremely slippery/poor trac-
tion surfaces at low speeds, the transfer case can be switched into 4WD Low, which multiplies engine torque 2.72
times and locks the clutch pack for maximum traction at all times. The Neutral mode allows the vehicle to be flat
towed behind another vehicle.

NV245 Transfer Case

1 - CLUTCH ASSEMBLY

7 - ANTI-ROTATION BRACKET

2 - OIL PUMP

8 - SHIFT MOTOR AND MODE SENSOR

3 - REAR OUTPUT FLANGE

9 - FRONT OUTPUT SHAFT AND FLANGE

4 - DAMPER

10 - LOW RANGE PLANETARY

5 - ROLL PIN

11 - INPUT SEAL

6 - SECTOR ROLLER

12 - DIFFERENTIAL

TRANSFER CASE - NV245 - SERVICE INFORMATION

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Electric shifting is accomplished with a T-handle transfer case lever in the shifter assembly to provide simplified
operation and positive engagement of 4 Low. A pushpin button is provided to shifting the transfer case into
NEUTRAL.

OPERATION

ACTIVE TRANSFER CASE CONTROLS

Controls for the NV245 transfer case active clutch (torque biasing device) are located in the Final Drive Control
Module (FDCM) and communicated on the CAN C bus. The FDCM monitors wheel speeds at the front and rear
axles to detect wheel slippage. A complete vehicle dynamics model calculates slip at each tire for given vehicle-
operating conditions. The clutch pack in the transfer case is engaged to minimize the speed difference between the
front and rear axle, resulting in torque transfer to the axle with higher traction. The electronically controlled wet
clutch pack uses an electric motor to actuate a sector plate. The sector plate actuates a clutch lever that applies
normal force to the multi-disc wet clutch pack bridging the differential. The clutch discs are alternately splined to the
front and rear driveshafts. When normal force is applied to this clutch pack, torque is transferred to equalize speed
differences between front and rear axles.

TRANSFER CASE MODES

The transfer case operates in active full-time four-wheel drive (4 High Full-Time) unless the driver chooses 4-wheel
drive Low or Neutral. A chrome T-handle momentary contact lever in the shifter assembly labeled 4WD Low allows
the driver to select 4WD Low when a set of conditions is met. A separate Neutral pushbutton switch located beside
the 4WD Low T-Handle is used by the operator to enter Neutral when a set of conditions is met. An indicator
located in the instrument cluster indicates when 4WD Low is active. There is an indicator next to the Neutral button
to indicate Neutral position as well as a message in the EVIC in the cluster that states “4WD SYSTEM IN NEU-
TRAL.”

ELECTRIC SHIFT MECHANISM

All of the switching functions use resistive multiplexing to tell the Final Drive Control Module (FDCM) which mode to
select. The FDCM operates an electric motor that shifts the transfer case. The FDCM obtains additional data nec-
essary for operation and to provide diagnostic outputs via the CAN network. The electric shift mechanism helps
protect the transfer case against internal damage by preventing a shift to 4WD Low range unless the vehicle speed
is below 3 mph (5 km/hr) and the transmission is in Neutral. To shift the transfer case into Neutral for towing the
vehicle, the pushpin button next to the range shifter must be depressed with a pen and a set of shift conditions must
be met.

Through communication with various modules over the CAN network, the FDCM knows vehicle speed, automatic
transmission position, engine run status, ignition status and brake switch position, some or all of which are required
to determine whether shifts between 4WD Low, 4WD High or Neutral will be allowed. Diagnostic outputs include
fault codes and the ability to “read” switch position and position sensor output. A warning message in the EVIC in
the cluster indicates if a malfunction occurs in the electricshift system. A motor and encoder (position sensor)
replace a lever on the shaft that shifts the transfer case. When a shift is called for, the motor turns the shaft until the
sensor indicates that the correct angular position has been reached. To prevent the transfer case from making unin-
tended shifts, the switch must be in position for 0.25 seconds before a shift will take place. A shift can take up to
1-2 seconds from the time that the switch is moved for full travel. If the shift is not completed in the appropriate
time, the module will repeat the action up to five times. Misalignment of the gears in the transfer case may block a
shift, in which case the sensor will detect this; the motor will then reverse and try again to complete the shift. Block-
age can occur if the vehicle is stationary when the shift is initiated, but if the vehicle is moving as recommended
when the shift is initiated, blockage is unlikely. If the shift is not completed after five attempts, the cluster indicator
will flash and the driver will have to return the switch to its former position and repeat the operation.

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TRANSFER CASE - NV245 - SERVICE INFORMATION

DIAGNOSIS AND TESTING

TRANSFER CASE - NV245

DIAGNOSIS CHART

CONDITION

POSSIBLE CAUSE

CORRECTION

Transfer case difficult to shift or will
not shift into desired range.

1) Transfer case electronically
controlled shift system malfunction.

1) Verify proper operation per the
appropriate diagnostic manual.

2) Insufficient or incorrect lubricant.

2) Drain and refill transfer case with
the correct quantity of Mopar

ATF

+4, Automatic Transmission Fluid.

3) Internal transfer case
components binding, worn, or
damaged.

3) Repair or replace components as
necessary.

Transfer case noisy in all drive
modes.

1) Insufficient or incorrect lubricant.

1) Drain and refill transfer case with
the correct quantity of Mopar

ATF

+4, Automatic Transmission Fluid.

2) Internal transfer case
components binding, worn, or
damaged.

2) Repair or replace components as
necessary.

Transfer case noisy while in, or
jumps out of, 4LO.

1) Transfer case not completely
engaged in 4LO position.

1) While rolling 2-3 MPH and the
transmission in NEUTRAL, or the
clutch depressed on vehicles
equipped with a manual
transmission, shift the transfer case
to the AWD or 4LOCK position, and
then back into the 4LO position.

2) Range fork damaged, inserts
worn, or fork is binding on the shift
rail.

2) Repair or replace components as
necessary.

3) Low range gear worn or
damaged.

3) Repair or replace components as
necessary.

Lubricant leaking from transfer case
seals or vent.

1) Transfer case overfilled.

1) Drain lubricant to the correct
level.

2) Transfer case vent closed or
restricted.

2) Clean or replace vent as
necessary.

3) Transfer case seals damaged or
installed incorrectly.

3) Replace suspect seal.

TRANSFER CASE - NV245 - SERVICE INFORMATION

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