Principles of Operation
Open Style Front Axle
The front drive axle receives rotational torque from the driveshaft. The direction of the rotation determines movement of the vehicle. The rotation enters the front drive axle through the drive pinion flange, turning the drive pinion and rotating the ring gear. The differential case houses the pinion shaft upon which the differential pinion gears ride. The pinion gears are in mesh with the differential side gears to which the axle shafts are splined. It is the unique arrangement of the differential that allows the axle shafts to be driven at different speed when needed, such as when driving around corners.
The open differential has the normal internal spider gear design that will allow a speed differential between the wheels when cornering.
DANA M190: The ring gear is welded with differential carrier assembly.
DANA M210: The ring gear is bolted with differential carrier assembly.
The front open style differential comes with and without a Front Axle Disconnect Actuator.
ELD
The front ELD is a device housed in the front axle. When activated, ELD allows both wheels on that axle to turn at the same speed providing added traction on slippery and/or off-road surfaces.
The front ELD system is operated by pressing the ELD switch in the SIMA. The SIMA is located in the center top of the instrument panel.
The front ELD is not available in Eco and Sport mode.
The ELD system consists of following components:
- ELD coil, located at the front differential
- Front differential assembly
- Electromagnetic dog clutch assembly
- AWD module
- ELD switch
The front ELD system can be activated per the chart below:
ELD Engagement/Disengagement Speeds and Availability -- 4WD Vehicles
| Drive Modes (4WD Modes) | Maximum Engagement Speeds | Automatic Disengagement Speeds | Automatic Re-Engagement Speeds |
|---|---|---|---|
| 4L | 32 km/h (20 mph) * | 41 km/h (25 mph) | 32 km/h (20 mph) * |
Drive modes are selected by using G.O.A.T. (go over any terrain) modes ATCM switch located on the center switch pack.
When the operator activates the ELD, the ELD icon displays in the IPC message center. If the vehicle is driven above the disengage speed, the IPC message center no longer displays the ELD icon, alerting the operator that the ELD is disengaged. Once the vehicle speed drops below the re-engage speed, the IPC message center displays the ELD icon again. If there is a malfunction with the ELD system, a CHECK LOCKING DIFFERENTIAL message is displayed in the IPC message center, letting the operator know the ELD is not engaged.
Under certain conditions the ELD system has the ability to modulate powertrain torque output as well as system engagement/disengagement to protect internal ELD hardware.
If the electronic locking differential is selected and the indicator in the cluster is gray or turns from amber to gray while driving, one of the following has occurred:
- The vehicle speed is too high.
- The accelerator pedal is too high during an engagement attempt.
- Your vehicle is experiencing an anti-lock brake activation.
- The left and right wheel speed difference is too high during an engagement attempt.
If the electronic locking differential is selected and the indicator in the cluster does not turn on, one of the following has occurred:
- The electronic locking differential is not allowed in the current drive mode and is accompanied by SELECTED LOCKING DIFFERENTIAL NOT AVAILABLE IN CURRENT DRIVE MODE in the information display.
- The electronic locking differential is not allowed in the current 4x4 mode and is accompanied by SELECTED LOCKING DIFFERENTIAL NOT AVAILABLE IN CURRENT 4x4 MODE in the information display.
- The system has malfunctioned and is accompanied by CHECK LOCKING DIFFERENTIAL in the information display. See your authorized dealer for assistance.
The ELD feature allows the ABS to override the engage state during special events. When this condition occurs the ELD icon turns grey on the instrument panel, dash panel switch remains amber.
The differential locks when a PWM controlled magnetic field coil located inside the differential energizes. This locks the differential side gears and creates the locked differential.
The ELD system also informs the customer when there is too much wheel slip to safely engage the ELD by displaying TO ENGAGE LOCKING DIFFERENTIAL RELEASE ACCELERATOR PEDAL message in IPC message center. When the ELD is engaged, the AWD sends PWM voltage to the ELD field coil located in the differential. This voltage is initially 98% duty cycle, and then tapers off after 30 seconds. In order for the AWD to activate the ELD, certain conditions must be met.
- ELD switch ON, on the center switch pack
- Wheel speed information via HS-CAN communication from ABS module
- Operating range (voltage 11.5-16 volts)
- DTC setting range (voltage 10-15 volts)
- Ignition in the ON position
- TP