dismantling a starter motor

[Dru]

My old starter motor jammed, a few months back, and I got a replacement motor, a Lucas TVS. Not v impressed with it; it seems a bit gutless, and it's now jammed just like the old one. As I can't find the receipt, and I'm curious anyway, I am trying to dismantle it to see if I can't fix it. It differs from the exploded diagram in the workshop manual, in that there isn't a split pin holding the shaft nut in place. The end looks as though it ought to accept an Allen key, but there doesn't seem to be a hex hole there. Any suggestions?

[Jefftav]

I think you need a special clamp to compress the spring so that you can distmantle the pinion bit of the starter motor? If the pinion is jammed on the shaft I think the motor would be u/s and if you can free it there is a good chance of this happening again.

I had similar problems to you and the local factor replaced my stater motor 3x and it still wasn't brilliant. The first one the pinion jammed on the shaft and the others wouldn't disengage from the flywheel properly. I have since bought a recon starter from Tom Roy and this works a lot better.

A local auto electrician told me that thsi is not uncommon as the parts to assemble these motors are manufactured quite poorly.

[bmcecosse]

You do need a little clamp to take the Bendix off - I made one - not difficult. But if it's not obviously broken just clean it with carb cleaner spray and get it moving nicely up and down the shaft. It should have NO lubrication - although some use graphite powder. Any lubricant just attracts dust/grit - and that's what jams it.

[Dru]

Thank you. That's a handy tip about the lubrication- I had wondered if it had failed because it was under-lubricated... sometimes you can just be so very wrong, can't you?

I've been jiggering around with Mole grips and vices and stuff, and getting nowhere yet, but shall persevere...and start looking for a replacement OLD starter

[Dru]

by the way, something worrisome occurs to me; apparently there are two sorts of motor, with different numbers of teeth on the whizzy-round bit. I assumed I'd been given the right one when I bought the replacement, but it has sounded horrid and graunchy from day one. Would it have actually worked at all if it had been the wrong one, I wonder?

[MarkyB]

It would probably sound horrid and graunchy if the Bendix (whizzy-round bit) had the wrong number of teeth and be more likely to jam.

The Bendix is held on with the round metal "clip" that is visible near the end of the starter shaft in your picture.

Is everything bog standard Minor?

[Dru]

pretty much so, though it's not the original engine. Sadly, I didn't think to check the number of teeth on the old one, so can't do a compare and contrast. Damn.

[IslipMinor]

The original starter pinion (aka 'whizzy round bit') had 9 teeth and the later ones 10 teeth. Improbable as it sounds they are interchangeable!! The later ones just spin the engine over 11% faster, assuming the battery is good. I replaced an original 9-tooth starter with a 10-tooth about 7 years ago and the cranking speed increase was immediately obvious, but have just got used to it now. I questioned the Lucas agent at the time, but was assured that it would be perfectly OK, and it has been.

If the new starter jammed as well, I wonder if the ring gear on the flywheel is worn to the point that it causes the jamming? I would not keep trying starters, as if they jam on a worn ring gear, it can bend the starter shaft, and then that causes jamming in its own right.

[bmcecosse]

Indeed as Richard says - the shaft may now be slightly bent........ I believe there are also 11 tooth versions around - how many does yours have ? Unless something is bent or cracked- it should come free with some cleaning and perseverance. I prefer the 9 tooth Bendix - it may crank slightly slower - but it should take less amps to do so - leaving more volts for the ignition! Even if you don't have the receipt - it is obviously new looking - so just take it back to the seller and demand a replacement - they should maybe remember you ?? Most of us keep everything to do with our classics - in a file - to be passed on eventually with the car.......

[Dru]

Right! Sorted... I hope!

I gave up on trying to free up the Bendix (always think of my grandma's washing machine when I see that word...) and too the starter back to the shop. It was 8 weeks ago that it was new... they gave me a nice <s>new</s> recon motor, which seems a far better bet than an identical new one.

I cleaned up the thread and the shaft with WD40, then sluiced it a bit with surgical spirit for good measure. And installed it, checking the state of the flywheel teeth before doing so. They seemed in good health. And the new motor goes beautifully. Thanks for the input, chaps!

[bmcecosse]

Well done - the teeth you show there look fine - the engine however tends to stop in the same place each time and you may find there is a section of the ring gear where the teeth don't look so healthy. Hopefully this new one will serve you well!