Hello Will,

It shouldn't be possible to have an odd toothed ring gear.
The gear should be on the clutch cover for all forward facing starter and the part number seems to have stayed unchanged until the rearward facing starter was fitted. With this change the ring moved onto the flywheel to suit the change of starter location. I think I'm right in saying for all of 24-32 the gear was actually machined into the clutch cover plate rather than a separate ring shrunk on, and fitting a new one means machining the cover to accept it. When I was looking at replacing a badly chewed gear it seemed very close to the mounting bolts, and I found a good S/H one instead. If the gear has been replaced before it could be possible that this has not ended up quite right and is causing a mesh problem, but i'd consider this very unlikely.

1924-1932 Gear machined on clutch cover Part BJ24 Herehttp://archive.a7ca.org/wp-content/uploads/PL_353D.pdf

Hope that helps.

Location: New Forest

Thank for all the suggestions,

I've now tried a "known to be working" starter motor, fitted as normal, and that is also making a horrendous grinding noise like a bad gear change.

I know how a BS starter should sound running on 12V and its nothing like this!

The engagement gear on the starter is not hitting the six mounting bolts holding the starter ring (clutch cover plate) to the flywheel.

The two mounting bolts holding the starter motor to the bell housing are not too long and therefore not touching the flywheel/starter ring.

The position of the spacing lug hole for locating the starter, along with the mounting hole positions are the same as the previous engine.

The mounting surface on the bell housing doesn't look as though its been machined at all in its life.

I can't see any newly graunched metal surfaces or any swarf anywhere, all looks normal.

I've tried looking into the motor as its fitted without the cover plate on the forward face of it to see if I can see whats going on, the gear looks as though its engaging and disengaging as normal.

The car push starts and drives as normal, so theres nothing fallen down into the bell housing causing the grinding noise.

I've tried raising the starter motor up with a piece of cardboard on each side to see if that helped, no difference.

I'm now going to try using a forward facing starter as fitted to the later 20s cars.

Does any one have any different suggestions?! Losing my mind a bit over this...

Cheers!

Location: Bishops Cleeve

Will, looks like you have covered most things so a last suggestion, the two bolts that hold the big rebound spring only just miss the starter casing, if you don't have the correct narrow head bolts or some slack in the bendix bushes it's very easy for contact to occur when you operate the starter. This can make the noise you describe. Ian M

I am still convinced your problem relates to the ring gear either being locally worn or the wrong type. Another thought have you checked the flywheel position relative to the crankcase i.e too far forward or back?

If you put the starter on another engine and it functions correctly the issue has to be with the flywheel.

Location: NZ

The replacement starter was fitted to my 1929 car and worked a treat, so I know the starter works, unless it broke like first one, the first time I put it on this engine. I've taken the starter off and spun it up on the battery and it doesn't make any terrible noises.

The bolts holding the bendix spring are the correct type with machined heads - good idea though!

The position of the flywheel relative to the holes on the crank case is the same as the first engine, so can't be a problem, the only thing I haven't done is to measure the diameter of the clutch cover plate and starter ring

Has anyone ever heard of a duff batch of clutch cover plates being made?

The engine was completely rebuilt by a reputable austin engine company several years ago and hasn't yet been run enough to have run in.

Thanks again!

Location: Bishops Cleeve

You could have the wrong starter ring fitted to the flywheel, the problem has to be related to the ring in some way, either worn, the wrong type, or fitted round the wrong way.

Location: NZ