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Re: MGA 1600 Dragging starter

To: "M. W. Jordan, Jr." <mw_jordan@mindspring.com>
Subject: Re: MGA 1600 Dragging starter
From: neil.cairns@virgin.net
Date: Thu, 06 Aug 1998 16:48:32 -0700
M. W. Jordan, Jr. wrote:
> 
> Neil
> 
> Thanks for the input.  I used white grease and will remove the starter this
> morning and clean it off.  What do you think about the springs?  Will they
> tire after years of non-use or do you think it is merely a function of too
> much goop on the bendix (old goop before cleaning and new, white grease after
> cleaning.
> 
> Too late for the ring gear rotation as the motor is back in place and all
> sealed up for the present.  I do wonder why moving the flywheel bolts will
> present a "fresh" face to the starter gear, though.  It seems to me that since
> the fly wheel is a rotating mass, the specific teeth offered to the starter
> pinion gear will always be random, based on where the flywheel was when the
> engine was shut down.
> 
> Thanks again
> 
> MW
> 
> neil.cairns@virgin.net wrote:
> 
> > M. W. Jordan, Jr. wrote:
> > >
> > > Good afternoon
> > >
> > > Well, the 1960 MGA 1600 I bought several weeks ago is on the road and
> > > running like a top.  Of course it should be after an initial tune up
> > > quieted things down enough to determine there was a very noticeable rod
> > > knock.  Pulling the oil pan allowed confirmation that the bearings were
> > > shot (this despite an alleged rebuild in the recent running past - the
> > > cylinders were fine with okay rings; the connecting rod bearings had
> > > been fitted, but the crank had not been ground so there was too much
> > > play.  And on top of all that, the main bearings had been replaced -
> > > .020 over except for one shell that was .010 over.  A patch of rust was
> > > discovered in the bearing cap which would bind - hence the shade tree
> > > mechanic's fix of a different bearing shell on one side of the center
> > > bearing).  All this led to a "proper" rebuild with crank turned down to
> > > .030, rods sized, cylinders honed and now its has 80 lbs oil pressure
> > > when hot at road speed, dropping to 60 lbs hot at idle.  New valve
> > > guides all around, new exhaust valves and I am a real happy camper.
> > >
> > > EXCEPT - the starter seems to be dragging at certain times.  Sounds like
> > > it is hitting up against the ring gear on the flywheel.  Took the
> > > starter off and removed the gear and springs and cleaned and greased
> > > real well - all to no apparent effect.  The toothed gear (pinion gear ?)
> > > on the starter shows minor but noticeable wear on the end.  Now this car
> > > sat for more than twenty years before I got hold of it.  Could these
> > > springs just be tired ?  The starter engages fine, but the noise that
> > > sometimes comes from the area is annoying, at best, and a little
> > > frightening  at worst.
> > >
> > > I note that Moss in their catalog (page 17) notes that " MGA starters
> > > have a habit of chewing up the flywheel ring gear." and goes on to
> > > suggest that the ring gear be checked when the clutch is replaced.  But
> > > they offer no suggestions as how to avoid or minimize the chewing.
> > >
> > > What suggestions do you have.  Replace the springs (easy); replace the
> > > starter (easier but more costly); duct tape the pinion gear and always
> > > park on a hill (not the best as the MGA usually lives in a flat floored
> > > garage.)
> > >
> > > Advice appreciated and acknowledged.
> > >
> > > M. W. Jordan, Jr.
> > > Marietta, GA
> >
> > The starter BENDIX DRIVE should be DRY, not greased or oiled at all. If
> > you oil or grease it, it will lock up. I know it sounds horrid, but it
> > is a fact, NO OIL, but bone dry. Also, it is advantageous to remove the
> > flywheel, and refit it one or two bolt holes, to present an UNWORN part
> > of the flywheel ring-gear to the starter. This way you get two extra
> > bites at the life of the ring-gear.
> >
> > I am surprised at the advice by MOSS, as once again this Lucas starter
> > and flywheel is identical to 900,000 Farina BMC saloons, 600,000 Austin
> > Cambridges, 500,000 Morris Oxfords, etc, etc, all of the 1950's and
> > early 60's. None has a name for ring-gear wear. My own 1622 Magnette has
> > done 154,000 miles, on the SAME starter and ring gear.
> >
> > Neil.


The engine always STOPS at one of two positions, as its is a four
cylinder, so the starter motor always hits the SAME two parts of the
ring gear on starting up. You have to imagine as a four stroke, the
pistons rise and fall in PAIRS, so one is always on COMPRESSION per
stroke, hence the flywheel stopping at TDC on one or other of the pots.
Extra life can be had by moving the flywheel around a bolt...an old
trick to save fitting a new ring gear. If you do not believe me, look at
any four cylinder engine out of the car, there will be two worn bits on
the ring gear, and two almost untouched parts!!!

There are TWO springs, the great big heavy one to absorb the 'throw' of
the bendix, and a light one INSIDE the bendix to assist the throw-off
after starting, and to keep the starter gear out of contact with the
flywheel with the engine running. This light one can break, or wear
away.

To get at it, if you have an early starter, there is a split pin in the
securing nut, if you have a later starter, there is a hidden circlip
under the end collar. This last method of fixing needs a spring
compressor to ease out the circlip. OR you can risk it going into orbit
by using a small screwdriver, compressing the spring in a vice. Make
sure the car is well outside the garage though.....

Neil

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