Starter Motor mesh with ring gear


Is this the normal amount mesh between the starter motor & starter gear, I would have thought it would have been more? As far as I know the flywheel is a 3.5 litre & the starter is a M45G.

Regards Peter

Looks like it needs a spacer to get a bit more engagement.

It looks as if you need to remove a spacer from the RHS of the pinion in the photo.


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Here is a photo which shows the wear on my starter on a 3 1/2 Mark V with about 125,000 miles of engine running using this starter.

Hmm, similar wear pattern on my '38 SS 2-1/2 L; 96,000 miles, original starter as near as I can tell.

I think the poor pinion was embarrassed to get too close to that pale green paint. :laughing:

Thank you all, it looks like the engagement I have is normal although I would have thought more would be better. It is only because the bell housing is off that it came to light.

regards Peter

It leads to the next question, though.
What would happen if you removed that spacer on the pinion shaft?
Would the engagement be better?
Would it not work at all?
Or is it an illusion, there is no spacer?

I just restored mine and put it back in, assuming it was right before, never though to look at something like this.


What do you think, would turning the pinion gear 180 deg introduce another 50% longer life regarding wear?


No, No, The Pinion has a chamfer on the leading edge to aid engagement with the flywheel. which has a matching chamfer. Turning this around would introduce poor meshing with the flywheel. Leave it alone!!!


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Hi Art,

Ok, got it! Thanks for the warning.


It is not always easy to confirm details from a photo, but it looks like there are two spacer rings on the pinion shaft. If so, I have not seen that before. I always considered that the pinion should present a full overlap of the ring gear teeth because there is a high torque to be handled and full overlap is essential to transmit the torque and for a long wear life for the teeth. Any less engagement would be poor engineering.

Can you draw the pinion back and check if these are actually two spacers? If so, I suggest that the thinner one should be removed and then the setup tested in-situ. The thinner one looks like it is enough to get the extra overlap.

As Art said, don’t reverse the pinion for the reasons stated. Also, the pinion is hardened steel and the ring gear is not and if a squared edge of the teeth were subjected to repeated impact, they would eventually chip and crack.

I may have a spare starter under a bench somewhere so I’ll see if it can confirm anything.


Hello Peter

Thanks for your in depth analysis, the spacer ring closest to the starter dog is hollow & covers & protects the small spring as the dog moves towards the flywheel, the ring closest to the starter motor appears to be part of the shaft.

Regards Peter

I found my spare scruffy starter and a pinion for one l have to rebuild. Note that the pinions don’t have the collar on the ring gear end like yours. It looks like you may have the wrong pinion.