Starter ring.

[TonyC]

Take nowt for granted. So problem is high torque starter doesn't always engage and getting more frequent. Removed starter motor, yes interior out, tunnel cover out etc etc. Pinion on motor looks not to bad, but there is marking on the ring gear teeth, but all in all it looks serviceable.

 

Dismantled starter and all looks as it should. Witness of teeth engagement on pinion shows two thirds as it should be.

 

Rebuild and test 1. Check that solenoid throws out the pinion.

Measure distance from front of engine plate to ring gear - 28.9mm. Engagement depth confirmed ok.

Test 2:- check that solenoid is thrown out and motor spins.

 

All as it should be except on further closer (and difficult) inspection of the ring gear it looks like chamfer on the teeth face the gearbox and not as you would expect for a pre engaged motor facing the engine. A search on the forum then suggests that this has always been an issue and there is no ring gear produced for a pre engaged starter motor. Is this true? Is there a solution? Is there a source for ring gear?

 

As usual all comments gratefully accepted.

[Mark69]

Hi Tony ,

Sorry can't help with your query, but just wanted to let you know a nos ring was posted on ebay a couple of days ago.

Mark

[peejay4A]

As far as I know all the 6 cylinder cars had preengaged starters so it's hard to believe that the ring gear was wrong all that time. I had no problems on my 6 when I shrunk on a new ring gear. I can't recall the taper being wrong but it was a while ago.

[RogerH]

Hi Folks,

can anyone clarify - do all pre-engage starter motors engage in the same direction.

 

Do they all push rearwards or, do others pull forwards.

 

Roger

[TRsixchris]

All the pre-engaged starters that I have seen push the pinion rearwards ie engage from the front of the ring. However the GT6 and possibly Vitesse use inertia starter motors where the pinion is pulled in and therefore engages from the back of the starter ring. The new ring gear I fitted to my GT6 had the teeth correctly chamfered (for the inertia starter) on the rear of the ring. There does only seem to be one type of ring gear fitted to the six cylinder cars - so correct for inertia starter and incorrectly chamfered for pre-engaged starters.

 

Chris

[peejay4A]

In which case it must be non critical to have a chamfer where a preengaged starter is used. Presumably because it only starts spinning after the pinion has engaged in the ring gear.

[RogerH]

Ten years ago or more there was problem with these new starters no engaging because the chamfer is on the wrong side.

Thus nothing to help it engage

 

Roger

[Nick Jones]

I run an ND compact starter (ex Toyota) on my Vitesse. This is the pre-engaged type and engages from the front. The car originally had an inertia starter fitted and thus has the ring gear chamfer on the rear. In spite of this the starter has worked perfectly for at least 15 years.

 

Likewise my PI had the standard factory-fit, pre-enaged starter fitted but the chamfer on the rear. It worked. On the saloons some (the 2.5s) use pre-enaged starters and some the inertia type. All have the chamfer on the rear AFAIK. The pre-enaged starters have (or should have) the chamfer on the starter teeth and don't need a chamfer on the flywheel to work. The inertia type however very definitely do need the chamfer to work which is presumably why the flywheel ring gear is chamfered that way. The saloons with pre-enaged starters do have a bit of a reputation for gradually knocking the ring gear off the flywheel until the starter will no longer mesh - might be worth checking whether yours has done this?

 

As semi-relevant aside, many years ago I fitted a Dolomite 1500 engine in my Herald. I used the inertia starter that came from the 1200 initially. That would engage about 1 time in 20 tries and make appalling noises for the other 19. Turned out the chamfer was on the front of that flywheel. I went back to the scrapyard and acquired the pre-engaged starter that had been on the engine. It worked beautifully. A while later, after the Dolly engine came to a grisly end, I fitted a 1500 Spitfire engine which has the chamfer on the rear (one of the few differences between 1500 Spit and Dolomite engines - what were they thinking of?) and the pre-engaged starter continued to work happily.

 

From all this I conclude that pre-engaged starters don't normally care about chamfer and your problem lies elsewhere.

 

Nick

[Guest ntc]

250/5 and early 6 had the inertia type at some point I have also seen the ring gear fitted the wrong way round,also you will find the gear will be worn in three points no matter what.

Edited March 10, 2017 by ntc

[B Fitzpatrick]

Take nowt for granted. So problem is high torque starter doesn't always engage and getting more frequent. Removed starter motor, yes interior out, tunnel cover out etc etc. Pinion on motor looks not to bad, but there is marking on the ring gear teeth, but all in all it looks serviceable.

 

Dismantled starter and all looks as it should. Witness of teeth engagement on pinion shows two thirds as it should be.

 

 

Maybe you have covered this already but my dilemma with starter motor not engaging all the time was the ring gear had come adrift on flywheel and was spinning and only catching on a high spot - which was a random event. Hopefully this is not your situation

 

Best of luck

Edited March 11, 2017 by B Fitzpatrick

[Stanpartmanpartwolf]

There's no way round this one; you'd think that turning a new ring gear round, so it faces forward, would help.

Of course, the chamfer then ends up on the wrong side of the teeth & seems only to make things worse.

This is true for both 4 & 6 cylinder engines, sadly.

[TonyC]

Thanks all for your replies and input.

 

Purchased a Wosp HT starter which has pinion with chamfered teeth. Discussed the problem at a recent visit to TRGB with a view to fitting a new starter ring. TRGB advised that the ring gear has chamfered teeth one side and straight cut teeth on the other. It must be fitted to the flywheel so as the chamfered teeth do NOT engage with the chamfered pinion.

 

Hence if you use a pre-engaged starter with chamfered pinion the straight cut teeth on the ring gear must face the engine. If you fit an inertia type starter with chamfered teeth, which pulls in from front to rear, then the ring gear must be fitted so that the straight cut teeth face the gearbox side of the flywheel.

 

Conversely if your pinion teeth do not have a chamfer the opposite is true.

 

I have not proceeded using this rational as yet. Unfortunately unable to do the work at this moment in time so unable to provide feedback, but TRGB claim that if you have a situation where chamfered pinion teeth engage with chamfered ring gear teeth, either using pre-engaged or inertia type starter motors, premature wear and early failure of the starting mechanism will result.

 

Could this be the reason for my early failure (only 14000 miles since rebuild) and that of other forum contributors who claim a similar outcome?

 

It occurs to me that this could be a good question to pose to Wosp, but I notice from their web site they don't enter into any dialogue with the public who just happen to be their customer (who was always king back in the day). Worth a try I guess.

 

Once again thanks for all help. Ongoing opinion gratefully received and will keep you posted on eventual outcome.

 

TonyC