Update: 3rd Differential lasts 2 months New Front Differential Implodes in 2 miles

[JohnnyBronco]

Let me post the offical description of the modes and transfer case operation. This is a good read for everyone so you are not questioning whether you should or should not be driving in a particular mode.

There should be zero issue using Sport mode or 4A all the time on roads if you don’t care about gas mileage and want top performance. I have Performance Tune and run 91, so I leave it in Sport unless I am doing long distance freeway driving. I use the 4H mode when off roading with lockers or one of the goat mode that also sets throttle response. I also have pedal commander for fine tuning.


Four-Wheel Drive Systems - System Operation and Component Description

System Operation

Four-Wheel Drive

The 4WD (four wheel drive) systems consists of:

* Transfer case
* Driveshafts
* Front axle
* Rear axle
* AWD module
* ATCM

The transfer case has five modes of operation:

* 2H - Two-wheel drive high
* 4A – Four-wheel drive auto
* 4H - Four-wheel drive high
* 4L - Four-wheel drive low
* Neutral – For recreational flat towing

(2H) OPERATION

When the ATCM is in (2H), power is delivered to the rear wheels only. This mode is appropriate for normal on-road driving on dry pavement and provides the best fuel economy. Torque is passed through the transfer case to the rear driveshaft at a 1:1 ratio. In (2H):

* The ATCM sends a (2H) mode status to the AWD module via the GWM .
* The transfer case clutch is at or below the kiss point.
* The reduction sleeve connects the input shaft and output shaft
* (2H) will momentarily be displayed in the message center at key up and after a 4WD to (2H) shift.

(4A) OPERATION

When (4A) is selected on the ATCM , the 4WD system provides electronically controlled four-wheel drive with power delivered to all four wheels, as required, for increased traction. (4A) is appropriate for all on-road driving conditions, such as dry road surfaces, wet pavement, light snow or gravel. Shifts from (2H) or (4H) to (4A) can be made at any speed. In (4A):

* The ATCM sends a (4A) mode status to the AWD module via the GWM .
* The shift motor positions the ball ramp device at the clutch kiss point when driving conditions do not require 4WD.
* The shift motor positions the ball ramp device to apply the clutch when wheel slip is anticipated or detected.
* The reduction sleeve connects the input shaft and output shaft
* (4A) is displayed in the message center.

AUTOLOCK

If the system is in (4A) and AWD module detects driving conditions that require greater 4WD performance, the AWD module temporarily turns on (4H). The message center displays 4X4 TEMPORARILY LOCKED. The 4WD system automatically returns to (4A) after the system no longer detects these driving conditions. The message center will temporarily display 4X4 RESTORED.

POWERTRAIN TORQUE PROTECTION

If the system is in (4A) and AWD module detects excessive stress or high energy going through the clutch (clutch is slipping excessively while the system is commanding max clutch torque), the shift motor will release the clutch and message center indicates 4x4 TEMPORARILY DISABLED. When the system had the ability to cool off, 4x4 operation will be automatically restored. The message center will temporarily display 4X4 RESTORED.

(4H) OPERATION

(4H) provides electronically locked four-wheel drive power to both the front and rear wheels for use in off-road or winter conditions such as deep snow, sand or mud. This mode is not for use on dry pavement. Shifts from (2H) to (4H) can be made at any speed. In (4H):

* The ATCM sends a (4H) mode status to the AWD module via the GWM .
* The shift motor positions the ball ramp device to completely apply the clutch.
* The reduction sleeve connects the input shaft and output shaft
* (4H) is displayed in the message center.

(4L) OPERATION

(4L) provides electronically locked four-wheel drive power to both the front and rear wheels for use on low traction surfaces but does so with an additional gear reduction for increased torque multiplication. Intended only for off-road applications such as deep sand, steep grades or pulling heavy objects. (4L) does not engage when your vehicle is moving above 3 mph (5 km/h); this is normal and should be no reason for concern.

Shifts to and from (4L) can only be made below 3.1 mph ( 5 km/h) with the transmission in Neutral. When performing this shift, wait until the 4x4 Shift in Progress message disappears in the IPC before moving the selector lever back to Drive. If the vehicle speed or transmission range is not within parameters, the message center will indicate the necessary action needed to complete the shift. In (4L):

* The ATCM sends a (4L) mode status to the AWD module via the GWM .
* The shift motor positions the ball ramp device to completely apply the clutch.
* The shift motor positions the reduction sleeve connecting the planetary carrier and output shaft
* (4L) is displayed in the message center.

NEUTRAL OPERATION

For recreational towing (all 4 wheels on the ground) the transfer case should be placed in Neutral.
Refer to: Neutral Flat Tow Activation and Deactivation (307-07B Four-Wheel Drive Systems - Advanced 4x4 with 4A Mode, General Procedures).

* The IPC sends a Neutral mode status to the AWD module via the GWM .
* The shift motor positions the ball ramp device to completely apply the clutch.
* The shift motor positions the reduction sleeve to only engage the output shaft
* “Neutral Tow Enabled” is displayed in the message center.
G.O.A.T. Modes

NOTE: Not all G.O.A.T. modes are available in each trim level.

The vehicle is equipped with Goes Over Any-type of Terrain (G.O.A.T.) Modes that allows the driver to enhance the off-road performance of the vehicle by selecting the mode best suited to the terrain and driving conditions. Each mode changes a number of the vehicle parameters within the engine, transmission, traction control and 4WD systems.

Normal

* For everyday driving. This mode is the perfect balance of excitement, comfort and convenience. This is the default mode after each ignition cycle, the driveline settings remain the same prior to the ignition cycle.
* (2H) is the default four-wheel drive mode. All four-wheel drive modes are selectable when in normal mode.
* The front electronic locking differential, if equipped is available when in (4L).
* The rear electronic locking differential, if equipped is available.
* The stabilizer bar disconnect is available if (4H) or (4L) is selected.

Eco

* For efficient driving. This mode helps deliver maximum fuel efficiency and helps to increase driving range.
* (2H) is the default four-wheel drive mode. (4L) is not selectable in eco mode.
* The front electronic locking differential is not available in eco mode.
* The rear electronic locking differential is available.
* The stabilizer bar disconnect is not available in eco mode.

Sport

* For sporty driving with improved performance handling and response. This mode increases accelerator pedal response and provides a sportier steering feel. The powertrain system holds onto lower gears longer, helping your vehicle accelerate faster.
* (2H) is the default four-wheel drive mode. (4L) is not selectable in sport mode.
* The front electronic locking differential is not available in sport mode.
* The rear electronic locking differential is available.
* The stabilizer bar disconnect is not available in sport mode.

Slippery

* For less than ideal road conditions such as snow or ice covered roads. This mode can be used for crossing terrain where a firm surface is covered with loose, wet or slippery material. Slippery mode lowers throttle response and optimizes shifting for slippery surfaces.
* (4H) is the default four-wheel drive mode. Both four-wheel drive modes are selectable in slippery mode.
* The front electronic locking differential is available when in (4L).
* The rear electronic locking differential is available.
* The stabilizer bar disconnect is not available in slippery mode.

Sand

* For off-road driving on soft, dry sand or deep snow. This mode may help get your vehicle unstuck from deep snow or sand.
* (4H) is the default four-wheel drive mode. (4L) is selectable in sand mode.
* The front electronic locking differential is available when in (4L).
* The rear electronic locking differential is engaged when in sand mode and is available in all selectable four-wheel drive modes.
* The stabilizer bar disconnect is available in (4H) or (4L).
Mud/Ruts

* For off-road driving. This mode enhances vehicle performance to traverse muddy, rutted or uneven terrains.
* (4H) is the default four-wheel drive mode. (4L) is selectable in mud/rut mode.
* The front electronic locking differential is available when in four-wheel drive low.
* The rear electronic locking differential is engaged when in mud/ruts mode.
* The stabilizer bar disconnect is available in (4H) or (4L).

Rock Crawl

* For off-road driving and optimum rock-climbing ability. Rock crawl mode optimizes the throttle and transmission response to provide you additional control of your vehicle.
* (4L) is the only four-wheel drive mode selectable in rock crawl, the system prompts you to put your vehicle into (4L) upon selection.
* The front electronic locking differential is available when in (4L).
* The rear electronic locking differential is engaged when in rock crawl mode.
* The stabilizer bar disconnects when in rock crawl mode.

Baja

* For high speed off-road driving. Baja mode optimizes the throttle control for better response and torque delivery.
* (4H) is the default four-wheel drive mode.
* The front electronic locking differential is available when in (4L).
* The rear electronic locking differential is available
* The stabilizer bar disconnect is available in (4H) or (4L).
G.O.A.T. Mode availability by series


Normal Eco Sport Slippery Mud Sand Baja Rock
Base x x x x x
Big Bend x x x x x x
OuterBanks x x x x x x
Wildtrack x x x x x x x
Black Diamond x x x x x x x
Badlands x x x x x x x

Component Description



All Terrain Control Module (ATCM)

The ATCM contains the G.O.A.T. modes rotary dial, 2H, 4H, and 4L switches. The ATCM is the logic module for the front and rear ELD , the stabilizer bar disconnect, and all G.O.A.T. mode features.

AWD module

The AWD module is the logic module for the four-wheel drive system. Multiple modules/system inputs are used for the four-wheel drive system to determine the percentage of torque to be transferred to the front wheels.

Transfer Case

A supplementary gearbox attached to the transmission. The transfer case directs power to the front drive axle via the front drive shaft.
Refer to: Transfer Case (307-07D Transfer Case - Advanced 4x4 with 4A Mode, Description and Operation).





Transfer Case
OPERATING PRINCIPLE

The transfer case delivers engine torque to the rear wheels and to the front wheels, when requested. The transfer case is mounted on the rear of the transmission assembly. The transfer case has an integrated low range gear reduction using the planetary gear set.

The transfer case has five different operating modes;

* Two Wheel Drive
* Four Wheel Drive - High Range
* Four Wheel Drive - Low Range
* Four Wheel Drive Auto
* Neutral (for recreational towing)

The transfer case is commanded via the mode select switch and the AWD module. The transfer case is electronically shifted via a shift motor mounted on the front of the transfer case housing. The transfer case is filled with lubricating oil which is circulated using a mechanical oil pump. The oil pump is fitted with a strainer to filter any debris.

In four wheel drive mode there is no speed differential between the front and rear axles. This can cause driveline windup when cornering on sealed surfaces.

The Advanced 4x4 with 4A Mode Transfer case is the center of the AWD system. It is a gearbox that attaches to the output of the transmission through a splined input at the transfer case. Torque from the transmission is transferred to the front and rear driveshaft depending on AWD mode.

The transfer case is equipped with an electronically controlled high torque capacity clutch which is located inside the case. This clutch is used to synchronize the speed of the front driveline with the rear driveline during 2WD to 4WD high (4H) or 4WD AUTO (4A) shifts. The clutch also provides torque to the front driveline in all 4WD modes. The transfer case is lubricated by a positive displacement fluid pump that channels fluid flow through holes in the rear output shaft.



Two Wheel Drive Operation

In this mode all torque from the transmission is passed through the transfer case to the rear driveshaft which passes through the rear axle and to the wheels.

Four Wheel Drive Auto

In this mode the transfer case system is active all the time and requires no input from the driver. The AWD control system continuously monitors vehicle conditions and automatically applies torque to the front driveshaft. This is done through the use of a multi plate clutch pack inside the transfer case that modulates torque delivery to a chain drive that is connected to the front driveshaft. I any wheel slip is detected on the vehicle or if the vehicle is in a handling event the AWD control system commands the transfer case actuator to apply torque to a ball ramp cam system which then applies an axial force into the clutch pack.

Four Wheel Drive High Range

In this mode the clutch is essentially locked. This would lock the front and rear driveshafts together giving the vehicle maximum traction. It is a similar mode to the ESOF system 4WD high (4H) mode

Four Wheel Drive Low Range

This mode operates the same as 4WD high (4H) but in addition the torque delivered to the transfer case from the transmission passes through a planetary gear set which multiplies the torque by the given ratio. ( In the case of the Advanced 4x4 with 4A Mode transfer case the ratio is 3.06:1 ) While the torque is increased by 3.06 the output speed from the transmission is reduced by the same 3.06 ratio.

This should be a thread of its own highlighted and bookmarked or maybe it is

Sponsored