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MG Midget and Sprite Technical - rear seal

A week or so ago I fitted my engine back in complete with a peter may rear seal.

Cutting a long story short I have removed the engine and inspection of the rear seal revealed a major fault.

I may have fitted incorrectly but the flyweel has been making contact with the seal and it is worn through and is kn4ckere.

Has anyone experienced anything similar?
Robert (Bob) Midget Turbo

Yes, when fitting I thought the whole thing looked like a disaster waiting to happen and I was right. I'd rather have a small leak from the original than the high chance of a massive one. I removed it and haven't looked back. Probably the worst mod I've tried on my car. Hope you get it sorted Bob.
John Payne

Robert did you also get a packing shim to place between the flywheel and the crank tail?

My Morris Minor Centre main seal kit had such a thin shim with it which moved the flywheel about 0.025"/0.030" to allow the flywheel to turn unrestricted by the seal material.
Bill 1

They are complete pants.

You own an A-series, let it drip.
PeterJMoore

mine works

and drips from enough other places...
Bill 1

Well I didn't get a shim for the flywheel nor any instructions accordingly.
However the problem could have be solved with a shim although I am not thrilled by that idea. I may based on the above information machine the flywheel to relieve the problem rather than shimming. It is just conforting to know there is a fundemental issue. :)
I will ring Peter on monday to see if he has any comment and hopefully he will send me a new seal?

Many thanks to all.
Robert (Bob) Midget Turbo

The ones I have seen have a shim

These are not recommended by Peter for high revving engines...

James B

Not on the same thread but noticed that Robert (Bob)midget Turbo posted a photo of one of the Jacobs Midgets at Silverstone back in June. I am gathering material for a new website about these 3 Midgets and wonder if he would be willing to let me have a high resolution copy of the photo (and any others of the car) if willing for me to use them. I was busy competing in the sprint on the Stowe circuit at the time so didn't get to see the car. If C Bintcliffe reads this may I also use the photo of my Sebring Sprite at that event on my sebringsprite.com website, pleaase? Any one else got any Jacobs or Milne Midget photos are info - would be gratefully received. Cheers Martin Ingall
M E Ingall

Bob
Mine has a shim also.(between crank & flywheel) IIRC it was bought from MMC or Frontline
Ian
Ian Webb '73 GAN5

I have shim too. Didn't you notice it was catching Bob when first installed?

The shim looked to be good quality. From memory it was about 0.5 mm thick. From Peter May.
Tarquin

Thought it was close I must say Tarq but assumed they all are and would be OK. It is masked when the flywheel is fitted.

Strangely enough one reason I took the engine out again was the mass oil leak coming from the front! the rear was dry! I was also having a problem with the clutch making a noise when the pedal was depressed. Thought it sounded like something was touching the oil pump cover, as it turned out to be. My new cover bolts were just a smidge too long and were occassionally catching it.
Bob Turbo Midget England

Sorry Martin missed your post

Yes as you are aware the Jacobs car is totally original and is a credit to the Malcolm Beer. :)

I have a number of photos from Silverstone last year as I am sure has Dennis that we will gladly share.

Email me at rjwelchmidget at aol.com
Robert (Bob) Midget Turbo

here is one photo


Robert (Bob) Midget Turbo

Very surprised??

I rang P May today expecting them to be helpful.
What a shock?
Said it was my fault for not fitting the spacer!!
What spacer I enquired?

Guess I must be lieing about not receiving one!

Never mind you live and learn!
Bob Turbo Midget England

Hi Bob,
Should be a spacer in the seal kit.However I spent years trying to get this thing to seal,both NA and turbo,many seal types,spacers,alignment jigs etc.in the end,like others I went back to a labyrinth and cured the problem!Well,it still weeps a bit,but previously it pxxxed out.
steve cowling

Many years ago I gave up buying "kits" of parts from MGOC because, despite making the suggestion, they couldn't be bothered to include a simple contents list of what was supposed to be in the kit. There was no real way as a purchaser of knowing if you had received all the parts that were intended to comprise the properly packaged complete kit.

It rather sounds as if the same simple expedient would have avoided this problem in your case, Bob. Equally, it would have protected the supplier had you been the sort of customer inclined to lie about the non-inclusion of the shim.

Guy
Guy Oneandahalf Sprites

Hi Steve for some reason I think they put my kit together from bits and I ended up with the alloy bits a tube of sealer, gaskets and the oil seal. All in a plassy reseal bag.
No instruction nor a spacer.
Never mind I will complain about my treatment to the trade scheme and pop down to my local partco and buy a new seal. Think I will machine my flywheel rather than make a spacer.

Just could not believe they did not simply send me a spacer and seal??
Robert (Bob) Midget Turbo

Now then, did I put that spacer back in the kit I sent back - I must check in the garage later!
John Payne

Martin

You are more than welcome to use my photos, do you need me to send you a bigger copy?

Carl
C Bintcliffe

Carl

Thank you very much. I have copied the photo which is fine just as it is. Thanks again.

Cheers

Martin

M E Ingall

I fitted a Peter May seal to mine.....with the spacer. It gave up the ghost after a couple of hundred miles halfway up the A34 on the way to Spridget 50 (needless to say we didn't make it and quite a few expletives were heard around the Tot Hill services area). Got it home took the engine out, fished the old scroll seal out of the parts box and sent it away to be line bored. All back in and installed, no leaks (at all) after a few thousand miles = very happy person. Simples!
Ali- Midget Mk1 1098

Just out of interest how thick was the spacer?

I have made some measurements and my flywheel needs to be at least 2.25mm further out to clear the seal.

I intend to machine 2.75mm off the centre hub to achieve the same thing

Anything less than 2mm would destroy the seal as soon as the engine was run.
Robert (Bob) Midget Turbo

Spacer is about 3mm from memory.
steve cowling

Just checked a damaged spacer,it's only about 1.5 mm
steve cowling

I was just wondering Steve

How many of these failed seals are due to the spacer not being thick enough. If I fitted a spacer of only 1.5mm the seal would be destroyed very quickly.
Robert (Bob) Midget Turbo

IIRC the recess in the 1275 flywheel that locates on the crankshaft is not very deep and I would want to make sure that the spacer was less than that depth to maintain the correct location.

Robert,

Shame about the P May reaction to your missing spacer claim, seems bad customer relations for a potential oversight and the minimal cost to correct.
David Billington

Yep I too was shocked by the reaction however not going to worry too much about that, you live and learn as they say.

The recess David is more than 5mm and so I will be machining 2.75mm off the flywheel boss which is about half. I thought this was a better solution than the spacer anyway.

I also think that I can get a new seal fairly easily from Partco so no big deal.
Robert (Bob) Midget Turbo

Bob
I found that the common or garden black Nitrile seals didn't last long on my rear seal conversion, the original seal was red silicone and a directional (for the correct rotation) type and sealed perfectly for 6 years, when I reverted to that type it worked fine again.
I suspect our cranks are not very round and the soft silicone seals cope better with the out of trueness/ovality.
Of course there is a cost implication, IIRC the black seal was about £3 and the silocone £18 ! Ouch

Ian
Ian Webb '73 GAN5

Thanks Ian

This morning totally out of the blue I had a delivery of a new seal, instructions and 2 spacers.

Considering your post Ian I think I will bite my tongue and not send this stuff back but will keep the rather expensive seal and fit it. :)

The shims by the way are 1.5mm Pretty certain I will not use these but will machine my flywheel. :)
Robert (Bob) Midget Turbo

I have always had excellent support from Peter and Chris,so I'm glad that they've sent those bits.
steve cowling

Is the thing with the holes in the spacer??


Daniel Thirteen-Twelve

Yes and it only fits the flywheel one way of course.
(I think...)
at the end of a long evening fettling the alloy arch fitting it took me ages to get the right set of holes lined up.

I did bolt the flywheel on without the spacer first but a "turn the engine over by hand session" showed me it was a requirement rather than a refinement. I was worried about spacing the flywheel further out from the end which was why I hoped to leave it off.

So far it has held out and done a job.

But I am always waiting for it to fail after all the doomsayers...
Bill 1

What is the thickness of the spacer?
Daniel Thirteen-Twelve

it is 1.5mm as I stated just above. :)

Suprised it isn't in a book? :)
Robert (Bob) Midget Turbo

Never had a problem with flywheel/crank integrity with the spacer,BUT it does push the flywheel/clutch housing back and can cause a foul with the bellhousing.
steve cowling

Bob
My rear seal kit is exactly like the one in Daniels photo, which has a red/orange seal, when I used a black nitrile type it failed but when I reverted to a silicone type as in the picture its almost perfect again. My spacer is as the photo and IIRC would be 1.5mm thick also.
Ian
Ian Webb '73 GAN5

This thread was discussed between 17/10/2010 and 01/11/2010

MG Midget and Sprite Technical index

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