Lotus Elan and Lotus Elan Plus 2 Forums

During the rebuild I fitted a geared starter.

Initially it worked well, doing the job nicely.

Of late, turning the key does nothing.

The starter won't engage untill getting the passenger to do the old trick of rocking the car in second gear, presumably then, once the ring gear has been shifted round slightly, the starter engages normally and the engine fires up normally.

Not good practice, as it always seems to fail when you least want it to !

So, question is: are geared starters operating on the back side of the ring gear -(which has no lead on the gear teeth?
Or are there other issues when swapping from the old inertia type, that can be avoided or addressed?

Does the ring gear need turning round ?

Does the number of pinion teeth affect it working?

Thoughts please?

Regards,

Phil.

Most, if not all, pre engaged starters operate from the engine side of the flywheel. Inertia starters from the gear box side.

I just installed a Dave Bean 110 tooth ring gear, and the way the teeth are chamfered on both sides of the ring gear, it does not make any difference, which way the ring gear is installed. What is important, is the spacing of the starter in relationship to the total engagement of the pinion. You want the contact area of the pinion to the ring gear to be in the center of the pinion.

In my case, the ring gear was installed on a Fidanza aluminum flywheel fitted on the Zetec engine I am installing in my Plush 2, compared to my S2, it is very plush. To make everything work with the 2000E bell housing and re-using the pre engaged starter from the graveyard dead TC that was removed, it required relocating the ring gear on the flywheel, as the Fidanza flywheel for the Zetec is approximately 1" closer to the engine than the TC unit. The 135 tooth ring gear supplied with the new flywheel, is also larger in diameter. I machined the flywheel ring gear flywheel contact area down to match the original diameter of the TC flywheel. in the process, also moved the ring gear .250" closer towards the gear box. This was not enough to get correct engagement, and required machining a new spacer, replacing the one that is made to work with the TC flywheel, to position the starter further forward towards the front of the engine. The starter is now correct aligned with the flywheel, and pinion engages and dis-engages as it should.

The ring gear on my engine is original, I'm pretty sure there's only one side with a lead.

Is there anything I could do to make it work ? ( without major surgery)

Phil,
In my experience a geared starter will work with an original ring gear. But as Prezoom implied you do need to check that the distance the starter ejects the pinion is sufficient to give full engagement of the pinion with the ring gear. Both of the geared starters that I have fitted to Twinks have fallen short in this area and I have had to reduce the thickness of the adaptor flange. One of the suppliers did tell me that longer pinions are available and are another way round the problem.
Cheers
John

The problem I had with my new starter was that it wouldn't release all the time. The manufacturer gave specs for indexing the pinion to the ring gear which was dificult to measure in the car, but doable. So check that. In my case, the problem turned out to be the upper backing plate (plate between back of engine and bellhousing) intruded slightly into the hole for the starter which offset the starter just enough to jam it. Maybe something similar is going on with yours. I had to releave the backing plate with a little grinder. If you ever have your engine out and know you are going to replace the starter, check the fit before it goes in the car.

I had a slightly different problem. The starter would spin but there was difficulty engaging with the flywheel ring gear. Eventually the front of the ring gear wore enough that the starter pinion didn't engage at all. I had a new ring gear fitted (the pinion was unmarked) and the mechanic who did the job for me found that the original ring gear had shifted back which was the root cause of the problem. He tack-welded the new gear in three places and it's been perfect since.

Gents,

Thanks for the technical replies, much appreciated.

More the issue with my set up is that, I regularly go to start the car and there's no action at all ! ( no noise or anything to suggest it's actually engaged).

What's the actual Operation of geared starter;??

Am I correct in assuming that under normal operation, when the ignition key is turned, firstly, (although not perceived to be moving), the starter pinion gear actually (quietly) travels into engagement with the ring gear, once this takes place, then secondly, some sort of electrical or latching action takes place, which then triggers the rotation movement, allowing the geared starter to turn the engine over??

In my case, it seem's like the the first action is not completing the necessary preparations, for the second action to take place?

Only when I rotate the engine manually (by rocking the car backwards and forwards in gear) does it seem that the starter pinion lined up with the ring gear, and allowed to mesh correctly.

I'm guessing here, but my thoughts make me think that if the pinion is not correctly meshed with the ring gear, the latching mechanism will not even attempt to turn the engine over?

Could the starter pinion just be snagged up against the ring gear, and not meshing at all - thus no go?

Or do you think this is being caused by a started fixing /alignment issue.

When it does crank on the key, it works very well, with no nasty noises or grinding of any sort.

It's just that the starting is intermittent.

Very annoying!

RSVP.

Regards,

Phil.

Here are a couple of picttures of the insides of a typical starter. As stated, turning the ignition key to "START" sends current to the starter solenoid. When energised, it pushes the pinion shaft outward to engage the ring gear and simultaneously makes the connection to turn the starter motor. If the pinion shaft doesn't go far enough the contacts for the motor won't be engaged. Glad I keep my old manuals!!

Not quite, the motor part is only powered up at the end of the engagement solenoid throw not at the same time as the solenoid. this is done by large contacts at the end of the solenoid usually, if the pinion cannot engage fully a spring behind the pinion clutch will compress allowing the solenoid to continue travelling to the end and make the contact for the motor. When the motor starts to turn the pinion gear should drop in and away you go!

I have come across weak solenoids in the past that do not have the force to compress the spring if the teeth don't mesh so every now and again, like yours, no go, although I would expect a small "clink" as the pinion hits the ring gear? Having said that if you still have the old pre engaged solenoid on the bulkhead your not going to hear much over the thump of that?

Regardless of anything else, the offset (fore and aft) measurement and the lash must be correct for it to work right. Remove the lower backing plate and you can see what you have. When I checked mine I made little feeler gauges out of bent and flattened saftey wire.

Webbslinger thanks for the reply.

Any chance you can expand on your recommendations please?

Ta,

Phil.

All:

Replies appreciated, however the main issue that I'm really concerned about is the fact that the pinion gear may not be able to engage with the ring gear, (because of where the ring gear stops after the last engine run.)

Any comments on the possibility of the original ring gears only being chamfered on one side - would this be the likely cause, as the starter engages ok sometimes.

If it were an alignment issue, it wouldn't work anytime would it??

My plus 2 has run for 25 plus years with a pre-engage starter entering from the wrong side of an original single chamfer ring gear without issue so if that is the problem it is not due to the lack of chamfer. My Esprit which was designed with a pre-engage starter and the chamfer on the right side occasionally does block but it always resolves itself if I try a couple more times it them works as the pinion moves a fraction on each attempt and the alignment slightly changes so it engages after a couple of attempts.

To help diagnose the issue what happens when the starter fails to turn the engine:

1. Does the starter start to spin but it grinds and does not turn the engine
2. Does the starter just make a click as the pre-engage mechanism works but it hits the flywheel but is blocked by the ring gear and does not try to turn as it has not traveled far enough to engage the starter turning
3. Does the starter engage and try to turn the engine but fails to do so for some reason such as excessive voltage drop in the system or mechanical misalignment jamming it.

which of the above determines what the fix is.

cheers
Rohan

Rohan,

Thanks for shaddowing this one!

I guess I'd have to say "option 2", so - I turn the key and - nothing!

To be fair, I don't even hear a 'click' as the pinion tries to engage.

But remember- sometimes it starts as it should.

Most times I have to engage 2nd gear and gently rock the car back and fourth......then the key is turned, the starter turns and then the engine turns and fires.

It's similar to when the old inertia type starters got stuck during engagement.....rocking the car would release the "binding" of the pinion and ring gear.

I think the previous prognosis is someway to being correct ...i.e. the pinion is coming to an halt against the ring gear, as it is not being allowed to mesh(or travel the necessary distance) to engage the motor.

I thought this 'improvement' would be good but have to admit, I'm nearly at the point of overhauling snd refitting the original inertia starter which I still have !

Any ideas (without having to extract the engine).??

I'd check to ensure that you're getting power to the starter EVERY time. Are you still using the external solenoid?