Table of contents: Dismantling the viscous fan ↓ Execution order ↓
Here you see a viscous fan (radiator fan) six-cylinder engine. Its components:
- 1 - fan blade;
- 2 - Viscous clutch axle - for a six-cylinder engine with a large hexagonal head mounting bolt;
- 3 - viscous adhesion.
To save power, this fan is equipped with a so-called viscous clutch. It switches on the fan at an ambient temperature of 82°C. This is done by means of a bimetallic strip, which, being temperature-dependent, releases viscous silicone oil into the working space of the viscous clutch through a valve. The oil creates a force closure between the belt pulley and the fan – the fan supplies cool air. At temperatures below 60°C, the silicone oil returns from the working space to the collector – the fan rotates at a lower speed, without consuming power.
Dismantling the viscous fan
Removing the viscous fan of a six-cylinder engine: to loosen the fan mounting bolt, you need to block the belt pulley: insert a screwdriver into the hole (2) and rest it against the bracket (1).
The same process described in the dismantled engine on the left is shown here in the car. The screwdriver is inserted into the hole (2) and rests against the bracket (1). The bolt (3) can be unscrewed.
Removing the viscous fan on a four-cylinder engine: the belt pulley (1) is locked with an M5 x 60 bolt (2), the mounting bolt can be unscrewed with an 8 mm Allen key (3).
Execution order
1. Four-cylinder engine: unscrew the 8 mm Allen key mounting bolt at the rear of the fan bearing. Lock the belt pulley by inserting an M5x60 bolt.
2. Remove the viscous fan.
3. Unscrew the fan coupling from it.
4. When installing, tighten the bolt to 70 Nm.
5. Tightening torque of the fan at the clutch: 10 Nm.
6. Six-cylinder engine: Loosen the fan mounting bolt (it is also the axis of the fan) with an open-end wrench SW 32.
Caution: left-hand thread! Block the belt pulley with a screwdriver. The screwdriver rests against the bracket provided for this purpose.
7. Remove the viscous fan.
8. Unscrew the viscous clutch on the fan.
9. When installing, tighten the bolt to 70 Nm.
10. Tightening torque of the fan on the clutch: 10 Nm.
[Information obtained from this resource «AUDImanual»]