starter motor pinion

[SRF]

i have just bought a replacement starter motor.  the new one has 9 teeth on the pinion and is very noisy. my old one has 10 teeth on the pinion.  The supplier ssys either 9 or 10 teeth both fit, is he right

[piman]

Hello SRF,,

as you have found out it does fit, but that doesn't mean that it is right. I would guess that a 9 tooth pinion will be slightly smaller in diameter than your original so does not mesh fully?

Alec

[Elma fud]

yer they probably fit because the diameter is the same but the pitch between the teeth will be way out which is why you are getting a lot of noise either the flywheel teeth or the starter pinion will wear badly, l'd get the old one rebuilt or get a proper 10 teeth starter.

[SRF]

I have the option of sending it back and having a 10 tooth pinion fitted, but because all the records they have show that the correct pinion for my vitesse should have 9 teeth,  I will have to pay for the pinion and carriage both ways.  I was just wondering which pinion is correct, before I decide what to do.  The one on the old motor is in very good condition so I may consider changing it over if I can rig a spring compressor.

[junkuser]

From what I heard, Lucas actually made the 9 tooth pinions to give a little extra push when these starters were used on the later, larger (?3 litre) Zephyr 6 engines.
Sounded odd to me when a chap asked me to keep an eye out for one for a Buckle he was restoring. This chap had been involved in Buckles pretty much since they were first built so I assume he knew.
He said they ran on the same ring gear as the 10.

[dinger]

if memory serves ,, 9 toothed pinions were more universal for BMC cars but Ford used 10 toothed units for Anglias - Mark 1 Cortinas etc .. Ford used to have a tendency for jamming starters when they had a few miles under their wheels .
There was a slight difference in tooth pitch between the two ..

[SRF]

I decided to swap the pinions over.  As I said I don't have a tool to compress the large spring, so  before I made one I tried a couple of carefully placed vice grips on the old one the pinion then came off quite easily.  There are couple of ways the spring is retained I have seen pins used and a key hole type washer.  On mine it is held on with a snap ring which is held in place by a recess in the end washer.  It was a bit fiddly but it came off.  If anyone attempts this be aware  the snap rings can fly.  One of mine did and I still  haven't found it.

The pinions are a straight swap   and when I refitted the starter it worked perfectly.  One little tip is when I removed the gearbox to replace it I reversed the bolts in the starter so the nuts are on the engine side.  It is still a bit of a fiddle but it saves having to remove the cover inside the car to refit the starter.

[Elma fud]

see you couldn't do that with a new car, good work around ;)