The starter is designed to start the car engine. It turns the flywheel, which in turn drives the engine's crankshaft.

1. 80 (89, 89Q, 8A, B3)
2. 80 Saloon (89, 89Q, 8A, B3)
3. 4000 (89, 89Q, 8A, B3)
4. COUPE (89, 8B)
5. 100 (4A2, C4)
6. 100 Saloon (4A2, C4)
7. 500 (4A2, C4)
8. 80 (8C2, B4)
9. 80 Saloon (8C2, B4)
10. 90 (8C2, B4)
11. 80 Avant (8C5, B4)
12. 100 Avant (4A5, C4)
13. CABRIOLET (8G7, B4)
14. A4 (8D2, B5)
15. A4 Saloon (8D2, B5)
16. A4 / S4 (8D2, B5)
17. A6 (4A2, C4)
18. A6 Saloon (4A2, C4)
19. A6 / S6 (4A2, C4)
20. A6 Avant (4A5, C4)
21. See more in applications

The starter construction

Electric motors are used with electromagnetic excitation or with permanent magnet excitation. The latter are more modern. They are more compact, simpler, consume less current and have a higher rotational speed, but less torque. Therefore, a gearbox is additionally introduced into the design of such starters to increase the torque.

The solenoid relay is designed to supply power to the electric motor and supply the drive gear to the flywheel rim. When the ignition key is turned to the “Start” position, power is supplied to the relay contacts.

The overrunning clutch (“bendix”) protects the BOSCH brand Starter motor from damage after starting the engine. As soon as the crankshaft rpm exceeds the starter motor rpm, the freewheel disconnects the drive gear and the motor shaft.