Check of the coupling of the drive of the cooling fan

Magnetic coupling

Cross-section of the magnetic coupling of the fan

1 — primary disk
2 — a hysteresis disk
3 — a secondary disk

4 — a permanent magnet
5 — a steel disk
6 — the ball-bearing


  1. On the stopped engine to a vreshcheyta the fan manually be also convinced that it rotates evenly and silently.
  2. Replace the fan coupling if it does not show resistance to rotation or works with noise.

Viscous coupling

Cross-section of the viscous coupling of the fan

1 — the coupling case (a secondary detail)
2 — a drive plate (primary detail)
3 — a shaft with a flange
4 — consolidation
5 — the needle bearing
6 — the cooling edges
7 — an oil scraper
8 — a spring

9 — a persistent finger
10 — a bimetallic plate
11 — a cover with the holder
12 — an intermediate washer
13 — the falling opening
14 — the valve lever
15 — the tank
16 — the working camera


  1. Warm up the engine up to the normal working temperature and support its frequency of rotation from 4000 to 4500 rpm. Do not close a radiator, otherwise the coupling will correctly not react to changes of temperature.
  2. By means of the thermometer (the index of temperature) be convinced that when heating the engine to 90 — 95 °C the speed of rotation of the fan increases approximately by 1000 rpm. At correctly working coupling it will be noticeable aurally. The faulty coupling should be replaced.