Re: Alfetta Starting Problem

[Simon Favre <favres@xxxxxxxxxxx>]

Paul Irvine wrote:

>This is a common problem in something like a Ford pickup that uses a
>bendix engage where the starter gear is driven outward on an inner
>helical gear as the starter motor begins to turn.

>But the Alfa starter uses an integral solenoid which engages the starter
>gear with a pivot fork while at the same time engaging the contactors
>which complete the starter power circuit.  So (as I understand it) the
>starter motor shouldn't even turn until the solenoid is fully retracted
>at which point the starter gear should be fully extended engaging the
>flywheel ring gear.

Not quite. If you fiddle with a starter motor out of the car, you'll
find that the gear can be turned easily one way wihout turning the
motor shaft. Turn it the other way, and it resists until the motor
shaft starts turning. All starter gears have some sort of one-way
clutch, commonly called a Bendix, whether or not it really is one.
This is to keep the engine from trashing the starter when it springs
to life. The flywheel will rotate the gear without spinning the motor
faster than it wants to go.  The fact that Alfa chose a different way
to get the gear out to the flywheel doesn't change the fact that they
do use a "Bendix" which may indeed be on its last legs.  I'd pull the
starter.

The engagement sequence is a little different.  I believe the contacts
engage and start the motor spinning just before the solenoid gets to the
end of its travel.  That way, the motor is starting to rotate just as it
tries to engage the teeth.  Otherwise, the gears might bounce off each
other, promoting rapid wear.

- ---
Simon

------------------------------