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Starter motor teeth

Posted: Tue Aug 02, 2016 6:42 pm
by mrbenn
Folks,

can I ask, how do the teeth look on this starter motor? I was thinking perhaps I should replace it, but I'm not sure how they are supposed to look. The teeth on a new one look to have a similar profile that suggested perhaps this one is still ok.

Image

Many thanks.

Re: Starter motor teeth

Posted: Tue Aug 02, 2016 7:18 pm
by bmcecosse
It's had it - and I hate to think what the teeth on the ring gear look like.... :cry:

Re: Starter motor teeth

Posted: Tue Aug 02, 2016 7:48 pm
by mrbenn
D'oh! I did buy a new starter motor. Would this likely prolong the life of the teeth on the flywheel, or shorten it? The old starter has 10 teeth, the new one has 9 if that makes any difference.

Best pic I have of the flywheel:

Image

Re: Starter motor teeth

Posted: Tue Aug 02, 2016 10:40 pm
by IslipMinor
9T or 10T?

When I bought the current starter about 10 years ago it had 10T against the original with 9T. I was very doubtful that it was a straight swap, but the Lucas man assured me that it was, and it certainly has turned out to be so.

The only difference is that the cranking speed is noticeably faster with the 10T pinion, so you may notice the reduction going the other way.

Re: Starter motor teeth

Posted: Wed Aug 03, 2016 7:44 am
by philthehill
An old trick with the Minor 4 bolt flywheel is to rotate the flywheel 90 degrees on the crank so that Bendix has a fresh bite on the ring gear when initially engaged.

Re: Starter motor teeth

Posted: Wed Aug 03, 2016 5:18 pm
by bmcecosse
9 or 10 teeth will be fine. But how did it get in this mess? Was the starter loose?

Re: Starter motor teeth

Posted: Wed Aug 03, 2016 6:22 pm
by mrbenn
IslipMinor wrote:9T or 10T?

When I bought the current starter about 10 years ago it had 10T against the original with 9T. I was very doubtful that it was a straight swap, but the Lucas man assured me that it was, and it certainly has turned out to be so.

The only difference is that the cranking speed is noticeably faster with the 10T pinion, so you may notice the reduction going the other way.
Old starter is 9 teeth, new one is 10. The new one (now fitted) does turn it over more slowly, now you mention it!
philthehill wrote:An old trick with the Minor 4 bolt flywheel is to rotate the flywheel 90 degrees on the crank so that Bendix has a fresh bite on the ring gear when initially engaged.
This flywheel has 6 bolts (1275) but I assume could be similarly rotated.
bmcecosse wrote:9 or 10 teeth will be fine. But how did it get in this mess? Was the starter loose?
Not on my watch, and we've had the car 15 years now. I thought the teeth were a little worn but didn't realise they were that bad!

Re: Starter motor teeth

Posted: Wed Aug 03, 2016 7:04 pm
by SteveClem
You've had your money's worth then. Looks better than mine did when I got my first Minor.

Re: Starter motor teeth

Posted: Wed Aug 03, 2016 7:17 pm
by IslipMinor
MrBenn,

The 10T pinion will turn the engine 11% faster that the 9T, assuming that the starter is in good condition, all the connections are good and the battery is also good and a decent size.

Re: Starter motor teeth

Posted: Thu Aug 04, 2016 8:23 pm
by mrbenn
Thanks for the info. I did wonder why it was turning over more slowly, didn't consider the effect of the different number of teeth.