PowerLite starter motor.

Post by Dave Plowman (News)
Anyone had one of these apart? They're aftermarket types often used to
replace early series wound Lucas types. They use a Jap permanent magnet
high speed motor with reduction gearing, so rather kinder on the battery.
Mine is out of warrenty, and sticks occasionally. Motor runs, but pinion
not engaged. It got quite a bit of oil on it, and the garage cleaned it
when sorting the leak. But that could be coincidence.
It's a awkward job to change on the street. So don't want to take it out
only to find it can't be fixed and then have to order up a new one.

Presumably it's the inertia type rather than a pre-engagement starter
with a solenoid and fork?

The pinion is on a spiral on the shaft and, when the shaft suddenly
starts rotating, the pinion's inertia causes it to move along the spiral
and engage with the starter ring on the flywheel. If it doesn't move
freely on the spiral, it can spin up at the same rate as the shaft, and
fail to engage. Sounds like that's what is happening.

For the pinion to move on the spiral, there needs to be some light
lubrication on it. If the garage cleaned *all* of the oil off it, that
might be what's causing the problem.

--
Cheers,
Roger

MrCheerful

2020-02-14 23:53:36 UTC

Presumably it's the inertia type rather than a pre-engagement starter
with a solenoid and fork?
The pinion is on a spiral on the shaft and, when the shaft suddenly
starts rotating, the pinion's inertia causes it to move along the spiral
and engage with the starter ring on the flywheel. If it doesn't move
freely on the spiral, it can spin up at the same rate as the shaft, and
fail to engage. Sounds like that's what is happening.
For the pinion to move on the spiral, there needs to be some light
lubrication on it. If the garage cleaned *all* of the oil off it, that
might be what's causing the problem.

no it is a pre-engaged type and it sounded rough when it went in.

Dave Plowman (News)

2020-02-15 11:56:33 UTC

Post by MrCheerful
no it is a pre-engaged type and it sounded rough when it went in.

Ah - forgot you'd once heard it.

But that one was replaced under warranty years ago and has been fine up
until now. Although some do say they sound odd in operation. I'd say just
different.

--
*I have my own little world - but it's OK...they know me here*

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.

Dave Plowman (News)

2020-02-15 11:53:24 UTC

Post by Dave Plowman (News)
Anyone had one of these apart? They're aftermarket types often used to
replace early series wound Lucas types. They use a Jap permanent
magnet high speed motor with reduction gearing, so rather kinder on
the battery.
Mine is out of warrenty, and sticks occasionally. Motor runs, but
pinion not engaged. It got quite a bit of oil on it, and the garage
cleaned it when sorting the leak. But that could be coincidence.
It's a awkward job to change on the street. So don't want to take it
out only to find it can't be fixed and then have to order up a new one.

Presumably it's the inertia type rather than a pre-engagement starter
with a solenoid and fork?

All this design are pre-engage.

Post by Roger Mills
The pinion is on a spiral on the shaft and, when the shaft suddenly
starts rotating, the pinion's inertia causes it to move along the spiral
and engage with the starter ring on the flywheel. If it doesn't move
freely on the spiral, it can spin up at the same rate as the shaft, and
fail to engage. Sounds like that's what is happening.

Not a Bendix drive. I'd be surprised if that is used anywhere these days.
But the original Lucas was pre engage too.

Post by Roger Mills
For the pinion to move on the spiral, there needs to be some light
lubrication on it. If the garage cleaned *all* of the oil off it, that
might be what's causing the problem.

--
*The colder the X-ray table, the more of your body is required on it *

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.

Roger Mills

2020-02-15 15:41:02 UTC

Post by Dave Plowman (News)
Anyone had one of these apart? They're aftermarket types often used to
replace early series wound Lucas types. They use a Jap permanent
magnet high speed motor with reduction gearing, so rather kinder on
the battery.
Mine is out of warrenty, and sticks occasionally. Motor runs, but
pinion not engaged. It got quite a bit of oil on it, and the garage
cleaned it when sorting the leak. But that could be coincidence.
It's a awkward job to change on the street. So don't want to take it
out only to find it can't be fixed and then have to order up a new one.

Presumably it's the inertia type rather than a pre-engagement starter
with a solenoid and fork?

All this design are pre-engage.

Not a Bendix drive. I'd be surprised if that is used anywhere these days.
But the original Lucas was pre engage too.

In that case, it seems odd that it spins without engaging. My
recollection is that this type only turned the motor on after the
solenoid had engaged the pinion.

--
Cheers,
Roger

MrCheerful

2020-02-15 17:46:25 UTC

Post by Dave Plowman (News)
Anyone had one of these apart? They're aftermarket types often used to
replace early series wound Lucas types. They use a Jap permanent
magnet high speed motor with reduction gearing, so rather kinder on
the battery.
Mine is out of warrenty, and sticks occasionally. Motor runs, but
pinion not engaged. It got quite a bit of oil on it, and the garage
cleaned it when sorting the leak. But that could be coincidence.
It's a awkward job to change on the street. So don't want to take it
out only to find it can't be fixed and then have to order up a new one.

Presumably it's the inertia type rather than a pre-engagement starter
with a solenoid and fork?

All this design are pre-engage.

Not a Bendix drive. I'd be surprised if that is used anywhere these days.
But the original Lucas was pre engage too.

Post by Roger Mills
For the pinion to move on the spiral, there needs to be some light
lubrication on it. If the garage cleaned *all* of the oil off it, that
might be what's causing the problem.

the starter pinion has a one way clutch in it (so that if you hold the
starter engaged it does not spin the starter too fast.) If that one way
clutch fails or is gummed up, then it is quite possible for the pinion
to be thrown in and the motor side to run, but it just doesn't turn the
pinion. That could be quite random as to whether it starts the car, and
may operate normally after a few tries (and the pinion warms a little)
It would also match well with your mention of the oil leak, particularly
if they dumped the starter in cleaner. (the guy that used to fix
starters/alternators for me would not accept any for repair if they had
been washed by the customer !! unfortunately he has now retired)

Roger Mills

2020-02-15 21:14:49 UTC

Post by Dave Plowman (News)
Anyone had one of these apart? They're aftermarket types often used to
replace early series wound Lucas types. They use a Jap permanent
magnet high speed motor with reduction gearing, so rather kinder on
the battery.
Mine is out of warrenty, and sticks occasionally. Motor runs, but
pinion not engaged. It got quite a bit of oil on it, and the garage
cleaned it when sorting the leak. But that could be coincidence.
It's a awkward job to change on the street. So don't want to take it
out only to find it can't be fixed and then have to order up a new one.

Presumably it's the inertia type rather than a pre-engagement starter
with a solenoid and fork?

All this design are pre-engage.

Not a Bendix drive. I'd be surprised if that is used anywhere these days.
But the original Lucas was pre engage too.

Post by Roger Mills
For the pinion to move on the spiral, there needs to be some light
lubrication on it. If the garage cleaned *all* of the oil off it, that
might be what's causing the problem.

I don't quite understand what you're saying.

We've now ascertained that it's a pre-engage type starter. This type
does indeed have a one way clutch - which allows the pinion to turn
faster than its shaft - but not vice versa. This prevents the engine
from driving the starter motor at 40,000 RPM or whatever if the pinion
remains in engagement after the engine has started. [Not a problem with
the earlier Bendix type because the engine in that case would wind the
pinion back down its spiral - causing it to disengage].

But that doesn't really explain how a pre-engage starter can spin
without rotating the engine. Unless the one-way clutch can fail in a way
which allows the shaft to spin *without* the pinion turning?

--
Cheers,
Roger

MrCheerful

2020-02-15 22:23:14 UTC

Post by Dave Plowman (News)
Anyone had one of these apart? They're aftermarket types often used to
replace early series wound Lucas types. They use a Jap permanent
magnet high speed motor with reduction gearing, so rather kinder on
the battery.
Mine is out of warrenty, and sticks occasionally. Motor runs, but
pinion not engaged. It got quite a bit of oil on it, and the garage
cleaned it when sorting the leak. But that could be coincidence.
It's a awkward job to change on the street. So don't want to take it
out only to find it can't be fixed and then have to order up a new one.

Presumably it's the inertia type rather than a pre-engagement starter
with a solenoid and fork?

All this design are pre-engage.

Not a Bendix drive. I'd be surprised if that is used anywhere these days.
But the original Lucas was pre engage too.

Post by Roger Mills
For the pinion to move on the spiral, there needs to be some light
lubrication on it. If the garage cleaned *all* of the oil off it, that
might be what's causing the problem.

the starter pinion has a one way clutch in it (so that if you hold the
starter engaged it does not spin the starter too fast.) If that one
way clutch fails or is gummed up, then it is quite possible for the
pinion to be thrown in and the motor side to run, but it just doesn't
turn the pinion. That could be quite random as to whether it starts
the car, and may operate normally after a few tries (and the pinion
warms a little) It would also match well with your mention of the oil
leak, particularly if they dumped the starter in cleaner. (the guy
that used to fix starters/alternators for me would not accept any for
repair if they had been washed by the customer !! unfortunately he has
now retired)

I don't quite understand what you're saying.
We've now ascertained that it's a pre-engage type starter. This type
does indeed have a one way clutch - which allows the pinion to turn
faster than its shaft - but not vice versa. This prevents the engine
from driving the starter motor at 40,000 RPM or whatever if the pinion
remains in engagement after the engine has started. [Not a problem with
the earlier Bendix type because the engine in that case would wind the
pinion back down its spiral - causing it to disengage].
But that doesn't really explain how a pre-engage starter can spin
without rotating the engine. Unless the one-way clutch can fail in a way
which allows the shaft to spin *without* the pinion turning?

that is exactly it, just as is often found on modern alternators, one
way clutchs do fail, I have seen three in the last two years on
alternators. I would guess that when starter one way clutches fail then
they get changed with the whole starter on spec. when it won't start,
rather than diagnosed and the actual part replaced. This would often be
done at the roadside, while the alternator one way takes longer to
develop as the vehicle still starts and runs, the only clue is some
squealing initially which fades as the load reduces or it warms up and
locks as it should.

Dave Plowman (News)

2020-02-16 14:11:29 UTC

Post by Roger Mills
We've now ascertained that it's a pre-engage type starter. This type
does indeed have a one way clutch - which allows the pinion to turn
faster than its shaft - but not vice versa. This prevents the engine
from driving the starter motor at 40,000 RPM or whatever if the pinion
remains in engagement after the engine has started. [Not a problem with
the earlier Bendix type because the engine in that case would wind the
pinion back down its spiral - causing it to disengage].
But that doesn't really explain how a pre-engage starter can spin
without rotating the engine. Unless the one-way clutch can fail in a way
which allows the shaft to spin *without* the pinion turning?

Makes sense. Is it a possible DIY job to replace the one way clutch -
assuming it can be bought as a spare?

I'm still just about up to working on things on the bench - unlike under
the car. ;-)

--
*I never drink anything stronger than gin before breakfast *

Dave Plowman ***@davenoise.co.uk London SW
To e-mail, change noise into sound.

MrCheerful

2020-02-16 15:47:48 UTC

Makes sense. Is it a possible DIY job to replace the one way clutch -
assuming it can be bought as a spare?
I'm still just about up to working on things on the bench - unlike under
the car. ;-)

I doubt that it would be available easily, although the starter should
be easy enough to take apart to replace it.

You could always go for a wosp 2kw version, only 300 sobs
https://www.autoelectricsupplies.co.uk/product/1185/category/226

Dave Plowman (News)

2020-02-16 14:08:41 UTC