4wd Coupling Assembly — Hyundai Santa Fe III (2012-2016)

Scheme 39

Scheme 39: Component Location

Scheme 40

Scheme 40: Components

Description

4WD ECU processes signals from various sensors and determines the current road and driving conditions. The ECU then utilizes this information to implement precision control over the 4WD coupling's multi-plate clutch and variably adjust the amount of torque delivered to the rear wheels.

Four Wheel Drive (4WD) Transfer Mode Selection

AUTO MODE: When driving in 4WD AUTO mode, the vehicle operates similar to conventional 2WD vehicles under normal operating conditions. However, if the system determines that there is a need for the 4WD mode, the engine's driving power is distributed to all four wheels automatically without driver intervention. When driving on normal roads and pavement, the vehicle moves similar to conventional 2WD vehicles.
LOCK MODE: This mode is used for climbing or descending sharp grades, off-road driving, driving on sandy and muddy roads, etc., to maximize traction. This mode automatically begins to deactivate at speeds above 30 km/h (19 mph) and is shifted to 4WD AUTO mode at speed above 40 km/h (25 mph). If the vehicle speed decelerates to below 30 km/h (19 mph), however, the transfer mode is shifted into 4WD LOCK mode again.

Scheme 41

Scheme 41: Electronic Coupling - 4WD Control (By Driving Condition)

Scheme 42

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Scheme 44

Cruising (Auto Mode) Power is delivered mostly to the front wheels.
Cornering (Auto Mode) Adjusts the amount of power to the rear wheels based on the turning radius and cornering speed.
Wheel Slip (Auto Mode) If one or both of the front wheels lose traction, the system transfers an appropriate amount of power to the rear wheels based on the slip amount at the front wheels.
Lock Mode Maximizes rough terrain performance (active only at speeds below 40 km/h).

Electronic Coupling

[Inactive]

Scheme 45

Scheme 45: Electronic Coupling

[Active]

Scheme 46

Operation Order

4WD ECU receives CAN signals from the vehicle's sensors.
4WD ECU calculates the necessary amount of rear-wheel torque and sends the corresponding driving current to the actuator (electronic motor and hydraulic pump).
Hydraulic pressure generated by the actuator moves the piston.
Friction from the piston's movement engages the clutch.
Power is delivered to the rear wheels.

Inspection

Note. All units are filled up with coupling fluid (ultra-low viscosity ATF) prior to shipping. Inspection, fill-up, and replacement of coupling fluid is therefore not necessary (zero maintenance, lifetime fluid).

Removal

Note. Coupling Maintenance Precautions Maintain the coupling at a horizontal level. (Scheme 47)the handling caution level (A) when servicing the coupling (removal, installation, replacement, etc.).

Scheme 47

Scheme 47: Removal

Scheme 48

Scheme 49

Scheme 50

Remove the 4WD coupling assembly bolts (A-3ea) mounted to the rear propeller shaft (B). Tightening torque: 49.0 ~ 68.6 N.m (5.0 ~ 7.0 kgf.m, 36.2 ~ 50.6 lb-ft)
Using a flat tool, separate the propeller shaft from 4WD coupling assembly.
Disconnect the pressure sensor connector (A) and Oil hydraulic Motor connector (B).
Loosen the coupling assembly mounting bolts (A-4ea). Tightening torque: 58.8 ~ 63.7 N.m (6.0 ~ 6.5 kgf.m, 43.4 ~ 47.0 lb-ft)
Using a flat tool, separate the 4WD coupling assembly from the rear differential carrier assembly.

Scheme 51

Scheme 51: Installation

Install in the reverse order of removal. NOTE: Smear the splines (A) with molybdenum type high pressure grease. When install the coupling, be careful not to damage the oil seal (B).
After replacing the coupling, reset the 4WD ECU's clutch clearing using the GDS tool. Refer to «ADJUSTMENT»(/hyundai/santa-fe/iii-2012-2016/remont/hoistjack/#general-information__adjustment) .

The 4WD ECM controls the Pump Motor Pump (Actuator) to generating an oil pressure. The pressure engages a multiple disk clutch to transfer torque to the rear wheels. The torque to the rear wheels varies according to the pressure on the clutch.

Scheme 52

Scheme 52: Description

Scheme 53

Scheme 53: Circuit Diagram

Information

If you have trouble code related to the oil hydraulic motor (actuator), check oil hydraulic motor (actuator) according to the inspection process.

Oil Hydraulic Motor (Actuator) Inspection Procedure

Scheme 54

Scheme 54: Inspection

Scheme 55

Scheme 55: Removal

Scheme 56

Remove the coupling assembly. Refer to «REMOVAL»(/hyundai/santa-fe/iii-2012-2016/remont/transfer-case/#4wd-coupling-assembly) .
Keep going perpendicular state after remove the coupling assembly. NOTE: Keep going perpendicular state during remove (install) the hydraulic motor (actuators).
Remove the hydraulic motor (A) after loosening bolts with hex wrench. CAUTION: Remove the hydraulic motor (actuators) after dropping residual oil as much as possible inside the coupling. (abut 5~10 sec)

Scheme 57

Scheme 57: Installation

Scheme 58

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Scheme 60

Scheme 61

Scheme 62

Before installation, wipe the surface with a clean cloth.
Check the O-rings (A) of the new hydraulic motor (actuators). NOTE: You have to prevent any dust from entering inside hydraulic motors (actuators) and housing.
Tighten the bolts after install the hydraulic motor (actuators). NOTE: When installing, motor connector has to toward in the direction of outside of the Coupling. Tightening torque: 8.8 ~ 10.8 N.m (0.9 ~ 1.1 kgf.m, 6.5 ~ 8.0 lb-ft) NOTE: When installing, oil can be reflux by the pressure in air breather hole. Change direction in the direction of the arrow and lay on the floor as shown in the illustration. * The reflux oil will flow to the bottom. You have to prevent additional backflow in according to order as shown in the illustration.
Wipe the flowed oil to around the surface with a clean cloth.
Install the coupling assembly. Refer to «INSTALL»(/hyundai/santa-fe/iii-2012-2016/remont/transfer-case/#4wd-coupling-assembly) .

The 4WD ECU makes a Motor Pump (Actuator) turn round for generating an oil pressure. And then it presses a multiple disk clutch and transfers the generated torque into rear wheels. Its torque value varies according to a pressure status.

Scheme 63

Scheme 63: Description

Scheme 64

Scheme 64: Circuit Diagram