4.2 flywheel ring gear damage

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#1 4.2 flywheel ring gear damage

Post by politeperson » Tue Apr 10, 2018 10:12 am

Looks like I have ring gear damage on the manual gearbox flywheel. A new flywheel appears to be £400.

I haven't a clue what caused it as I have a new Fosseway starter motor and dont remember seeing this damage last time the engine was out.

Any one machined off the old ring gear and fitted a new ring gear?

Anyone have a good flywheel for sale s/hand

I assume I have 133 teeth (as per 4.2 engines).

James
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#2 Re: 4.2 flywheel ring gear damage

Post by politeperson » Tue Apr 10, 2018 3:01 pm

Found a ring-gear. David Manners 133 teeth £29.

Answered my own question.

James
Its true, but Enzo never said it
Too many E types
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#3 Re: 4.2 flywheel ring gear damage

Post by christopher storey » Tue Apr 10, 2018 3:03 pm

Are you referring to the circumferential markings about half way down each tooth ? If so , could it be that the starter pinion has not been meshing with the teeth ? That suggests that the starter shaft is mispositioned in relation to the diameter of the flywheel. I think you need to check that it is indeed a 133 tooth gear, and not a 104 or even the old 132 tooth one, which are different diameters . Starter misposition is often the result of mixing starter, bellhousing , and flywheel between 3.8 and 4.2 components - ask me how I know....

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#4 Re: 4.2 flywheel ring gear damage

Post by mgcjag » Tue Apr 10, 2018 5:58 pm

How do you replace the ringear......machine it off or use heat to remove.....and to replace use heat again? Steve
Steve
69 S2 2+2 (just sold) ..Realm C type replica, 1960 xk150fhc

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#5 Re: 4.2 flywheel ring gear damage

Post by politeperson » Tue Apr 10, 2018 7:39 pm

Hello boys.

Yes I will definitely check I have the correct 133 tooth starter from Fossway. Its a mystery how this damage could have occurred.

To remove the ring gear it has to be machined off and heat used to refit it. I shall try and get some pictures of the process.
Its true, but Enzo never said it
Too many E types
XK120 SUs

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#6 Re: 4.2 flywheel ring gear damage

Post by mgcjag » Tue Apr 10, 2018 8:29 pm

Hi James...is there a spacer that fits between Fossway starter and bellhousing......also is your bellhousing a 4.2 one....it should have a recess in each of the bolt holes that the starter bolts to... Steve
Steve
69 S2 2+2 (just sold) ..Realm C type replica, 1960 xk150fhc

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#7 Re: 4.2 flywheel ring gear damage

Post by politeperson » Tue Apr 10, 2018 9:05 pm

Hello Steve,

I will have a look at the bellhousing. Its probably a 4.2 one.

I didnt take a spacer off, so I can only assume I didnt fit a spacer a year ago.

I will check with Fossway tomorrow.

Here is the starter.


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#8 Re: 4.2 flywheel ring gear damage

Post by christopher storey » Wed Apr 11, 2018 8:34 am

I'm still puzzled about what is actual damage which would require the ring gear to be replaced - and the witness marks on the Fosseway pinion look pretty normal to me

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#9 Re: 4.2 flywheel ring gear damage

Post by politeperson » Wed Apr 11, 2018 5:33 pm

I will get some pics of the damage tomorrow Christopher.

It is fairly unpleasant.
Its true, but Enzo never said it
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#10 Re: 4.2 flywheel ring gear damage

Post by politeperson » Thu Apr 12, 2018 9:51 am

Caught it just in time. John was just about to give it a shave.

The flywheel has three damaged areas like this.

James

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#11 Re: 4.2 flywheel ring gear damage

Post by christopher storey » Thu Apr 12, 2018 12:01 pm

yes... well I agree that it is best to machine it off and shrink a new one on . The old method, by the way, was to heat the ring gear in engine oil to about 150 - 200 degrees C when, if the flywheel is machined to a diameter which just gives an interference fit , it should slip straight onto the flywheel . This method is less likely to affect adversely the temper of the new ring gear than the rather quicker but brutal way of heating with oxy or the like

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#12 Re: 4.2 flywheel ring gear damage

Post by politeperson » Thu Apr 12, 2018 8:38 pm

Thanks Christopher, well its probably on now, i shall find out tomorrow.

Steve, I spoke to Simon from Fossway earlier. The starter should have been fitted with the starter spacer!

It looks like its absence was the cause of the issues.

I dug around in my spares collection and found it, so now I am just waiting for John to finish the crankshaft work so I can slap it all back together.
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#13 Re: 4.2 flywheel ring gear damage

Post by mark10337 » Thu Apr 12, 2018 8:41 pm

oh dear. now you've got me thinking. Which model of starter is it? I got mine from Rob Beere and there is definately no spacer fitted with it.
-Mark

1969 Series 2 OTS, Regency Red
'Life's to short to drive a boring car'

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#14 Re: 4.2 flywheel ring gear damage

Post by mgcjag » Thu Apr 12, 2018 9:24 pm

Hi Mark...the standard setup for a 4.2 is with a spigot plate between the starter motor and bellhousing https://www.sngbarratt.com/uk/#!/Englis ... c141e49282 so if you replace the starter you need to find out if you use the same plate... Steve
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#15 Re: 4.2 flywheel ring gear damage

Post by politeperson » Fri Apr 13, 2018 7:45 am

This is the Fossway Starter.

I seemed to work fine without the spigot plate, however it was secretly chewing up the ring gear.

It will be fine once I reassemble it with the spacer.

James


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#16 Re: 4.2 flywheel ring gear damage

Post by mgcjag » Fri Apr 13, 2018 8:07 am

Hi James...there are also small bush/locators that fit in the bolt holes on the plate to centralise it on the bellhousing....you should see that the bellhousing has partially enlarged bolt holes to accept the bushes.. Steve
Steve
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#17 Re: 4.2 flywheel ring gear damage

Post by mark10337 » Fri Apr 13, 2018 9:15 am

If the holes need to be enlarged slightly on the bell housing for the bolts, then this is not quite a fully reversible mod that has been alluded to in years of other posts, or is this just peculiar to the Fosseway starter motor replacement. It would be good to capture some of these things / variances between models in the upgrade section for reference.

The unit I was supplied from Rob Beere is the PowerLite RAC03 - a "Direct replacement for original starter on Jaguar 4.2 E-Type with 29mm pinion"

There were definitely no other mounting bushes, etc. mentioned in any of the fitting instructions etc. There may have been a spigot plate with it. I'll have a look but I'm away from the car at the moment.
-Mark

1969 Series 2 OTS, Regency Red
'Life's to short to drive a boring car'

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#18 Re: 4.2 flywheel ring gear damage

Post by Hugo » Fri Apr 20, 2018 1:51 am

mgcjag wrote:
Tue Apr 10, 2018 5:58 pm
How do you replace the ringear......machine it off or use heat to remove.....and to replace use heat again? Steve
Hacksaw as far as you can through it, then split it with a sharp chisel and a bigammer. Simples!
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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#19 Re: 4.2 flywheel ring gear damage

Post by Hugo » Fri Apr 20, 2018 2:00 am

politeperson wrote:
Thu Apr 12, 2018 8:38 pm
Thanks Christopher, well its probably on now, i shall find out tomorrow.

Steve, I spoke to Simon from Fossway earlier. The starter should have been fitted with the starter spacer!

It looks like its absence was the cause of the issues.

I dug around in my spares collection and found it, so now I am just waiting for John to finish the crankshaft work so I can slap it all back together.
One thing I can say from my own experience with my wife's Morris Minor is that the meshing of starter & ring gear is more critical than you might imagine. I fitted an after-market engine backplate when I upgraded her car to a 1275, and the register for the starter was a fraction off. I thought it could not be the case, since the bolt holes both lined up ok, but there was a millimetre or two of slack there that allowed the starter to be ever-so-slightly off. As I established after it had eaten its third ring-gear. Only an evening's work on a Morris Minor though, unlike some cars I could mention.
But what is this 'spacer' of which you speak? I have fitted one of these reduction starters to my E-Type, and I don't recall seeing a spacer. Can't remember where I got it though. I fitted one to my wife's Morris also - the starter from an American Isuzu Trooper fits a BMC A series perfectly!
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD

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#20 Re: 4.2 flywheel ring gear damage

Post by mgcjag » Fri Apr 20, 2018 7:43 am

Hi Hugo....have a look at the link i posted above.....it shows the Spacer..actually a Spigot plate.....its fitted on the 4.2 between the bellhousing and the starter motor..its shown on most of the parts diagrams....unfortunatly its hit and mis when you remove the starter if the plate is left behing on the bellhousing or comes away with the starter.....so when you fit an aftermarket starter you need to confirm with the manufacturer if it needs a spacer added.....Steve
Steve
69 S2 2+2 (just sold) ..Realm C type replica, 1960 xk150fhc

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