The Corolla AE92 GT-S Project

A website about my ongoing project

Nederlandse vlag Engelse vlag

4A-GE Starter motor refurbishment

The starter motor of the 4A-GE turned out the be a reduction starter motor.

For those of you who don't know what that means: With a 'normal' starter motor, the bendix (the little cog that comes out of the starter to rotate the flywheel) is fixed to the axle of the electric motor and is pushed out by a separate spool.

The electric motor of a starter motor generates the most power at low rpm's. That's when the load on the electric motor is highest and it draws the most power from the battery. That is really stressful for the battery, cables and such.


Using a reduction starter motor you can use smaller, lighter and less powerful electric motors.

The bendix of these starter motors is not directly fixed to the axle of the electric motor, but it is coupled via a little gearbox (usually a planetary gear system) to reduce the gear ratio. This way, a smaller electric engine can be used which reduces weight, size and current draw of the starter motor, while torque applied to the flywheel of the combustion engine can be higher.


 So it's a nifty little thing, but it could still use a little refurbishing.


Starter motor


So you guys know the drill by now. We'll start with disassembling the starter motor first so we can see what needs doing.


Starter motor partially disassembeld


Electric motor


The electric motor didn't look all that bad. The brushes were still large enough and didn't need to be replaced. So I left them alone. I did have to drill out the head of the bolts that hold the housing as they were broken. But luckily, I was able to remove the remaining bolts without any further drilling or grinding so they could easily be replaced.


Gears of starter motor


Starter motor parts


The running gear completely disassembled. Everything has been cleaned, parts that needed it have been sandblasted and put together again with a bit of fresh grease to make it run smooth and silent again.


Parts sandblasted


Parts sandblasted and painted


All the external parts were sandblasted and given a fresh coat of paint to make them look good again and prevent corrosion in the near future.

Now the starter motor could be reassembled and await installation in the car again.


Finished starter motor