Removal and installation a fan with a viscous coupling (BMW 3 Series E46)

320i, 323i, 328i with air conditioning

The viscous coupling fan is attached to the coolant pump shaft. Together with the electric fan, its job is to supply sufficient air through the radiator.

The fan clutch must be replaced if the hub has scoring and wear. In this case, the fan does not rotate or rotates with difficulty when the engine is stationary. The clutch must also be replaced if the axial or radial clearance exceeds 0.6 mm. To check, move the fan in the longitudinal and transverse directions. In this case, oil should not leak from the hub.

Removal

1. Remove the intake air guide by using a small screwdriver to remove the clips.



2. Unscrew the fan from the coolant pump hub using a 32 mm wrench.

The fastening nut has a left-hand thread and must be turned to the right to loosen (arrow on the illustration).

When unscrewing the nut, the hub must be held from turning with a V-belt. If the nut is particularly tight, you can tap the key with a hammer. The BMW service station uses a special tool for this, with which the pulley is held by the bolt heads. After unscrewing the nut, it can be twisted further by rotating the impeller. Make sure that the impeller does not fall. The fan is removed upwards.

3. Disconnect the impeller from the viscous coupling by unscrewing the screws (arrows in the illustration) and remove the coupling.

Installation

4. Insert the viscous coupling into the impeller and secure it with screws to a torque of 10 Nm.

5. Secure the fan with the coupling to the coolant pump hub with a torque of 40 N·m. At the same time, hold the hub from turning using the V-belt or bolt heads.

6. Insert the intake air guide and secure with clamps.