Starter whines when turning the key

Starter whines when turning the key

If your starter whines when you turn the key, you probably have a failing starter drive, also called a “Bendix.” The starter drive contains a gear to mesh with the flywheel and a one-way clutch. The clutch is designed to transfer rotation and torque from the starter motor to the flywheel during cranking.

Once the engine begins to fire on its own, the flywheel rotates much faster than the starter motor. To prevent the engine from driving the start motor at high speeds that would damage the motor, the clutch allows the starter drive gear to freewheel and then disengage from the flywheel and spin backwards into the starter.

Starter drive clutch symptoms

It’s the clutch in the starter drive that wears and causes starting problems. The first sign of clutch wear is a whine sound when you first try to start the engine. It sounds like this:

Multiple starting attempts can heat up the starter drive and make it work

As the starter shaft spins in the starter drive clutch, the clutch warms and can then engage. So it may take 3 or more attempts before the starter works properly. Don’t kid yourself, this is not a fix. You must either replace the starter drive or replace the entire starter. One day it will fail completely.

Replacing a starter drive requires the complete disassembly of the starter

©, 2022 Rick Muscoplat