The electronic locking differential consists of the following components:
• | Differential Bearing Retainer Race |
• | Differential Bearing Race |
• | Differential Bearing Assembly |
• | Locking Differential Coil Assembly |
• | Locking Differential Coil Plate |
• | Locking Differential Ball Bearing Plate - Outboard |
• | Locking Differential Ball Bearing Assembly |
• | Locking Differential Ball Bearing Plate - Inboard |
• | Locking Differential Clutch Spring |
• | Locking Differential Clutch Spring Retainer |
• | Differential Carrier Lock Pins |
• | Differential Pinion Gears and Thrust Washers |
• | Locking Differential Side Gear and Thrust Washer |
• | Differential Side Gear and Thrust Washer |
The electronic locking differential is a combination of an open differential
and an electrically energized coil assembly. When the coil is not energized, the differential
operates in the same manner as an open differential. The locking differential coil
assembly is located on the left side of the differential case. The locking differential
coil is held stationary within the differential case housing through the lock tab
on the coil and the hold down lock that attaches to the differential bearing cap.
The remainder of the locking components: the locking differential coil plate, the
locking differential ball bearing plates, the clutch springs and the lock pins are
located within the differential case and rotate at the same speed as the differential
case. The locking function of the differential is accomplished by a combination of
vehicle and user inputs. In order to the differential coil to energize, the vehicle
must be operating under the following conditions:
• | The transfer case indicator switch indicates 4 LO. |
• | The vehicle's speed must be less than 4.8 km/h (3 mph). |
• | The differential lock switch is turned ON. |
• | The left to right rear wheel speed difference is less than 50 RPM. |
Once the above conditions are met, the automatic transfer case shift control
module sends a signal to energize the coil. The energized coil creates a magnetic
field that allows the outboard locking differential ball bearing plate to rotate at
a slower speed than inboard locking differential ball bearing plate and the differential
case. The difference in the 2 speeds causes the ball bearings that are between the
outboard and the inboard ball bearing plate to move along their respective ramps and
separate the 2 ball bearing plates. The separation increases the width of the plates
and allows the differential lock pins to be pushed through the differential case towards
the locking differential side gear. The locking differential side gear has 6 notches
that accept the differential lock pins. Once the differential lock pins are engaged,
the locking differential side gear can no longer rotate independently of the differential
case. Since the locking differential side gear is now apart of the differential case
and turning at the same speed as the ring gear, the pinion gears that are perpendicular
to the locking differential side gear, cannot rotate within the differential case.
This causes the bell-side differential side gear to rotate at the same speed as the
locking differential side gear. The driving force generated by the ring gear, is transmitted
through the locking differential side gear, through the pinion gears, to the bell-side
differential side gear. The axle shafts, which are splined to each side gear, receive
the force and rotate together at the same speed along with the differential case and
ring gear. The will remain the locked position until the vehicle's speed exceeds 32 km/h
(20 mph) or the operator turns OFF the differential lock switch or the transfer
case is shifted into 4 HI, 2 HI or NEUTRAL. The locking differential
coil will de-energize and the differential will function as an open differential.