Rear Main Journal Flange

[Colin]

Hello everyone,
For a long time my Minor has had a knocking noise. You may have heard it last summer. The car has been off the road since the summer rally
I (and others) have had the whole engine to bits over it and eventually discovered the problem.
The “Rear Main Journal Flange” has split open along the edge of its keyway. (its weakest point).
this is the machined centre piece for the flywheel that connects to the crankshaft.
It’s the original type (1929) which is parallel using a keyway rather than the later (and better) tapered kind.
My understanding is that many of the original engines will have the later type fitted when the crankshaft is renewed.

If this is so then hopefully there will be one of these obsolete flanges sitting on garage shelf somewhere.
Is there anybody out there who might be able to help.

I don’t want to replace the crankshaft because there is little wear on it. But I suppose I might have to if I can’t get this part.

[Ian Grace]

Colin,

Looks like the new password worked. Great stuff!

[Colin]

Yes. thanks Ian
This topic makes me feel like a real tecky.
I suppose it would be possible to have one made, although i would need the specification.
Could the original broken one be used as a template even though its split

[Colin]

My plea seems to be falling upon stony ground
I shall have to get a new one made I fear. Can anyone recommend a good, but reasonably priced engineering workshop that might want to take this on?

[Ronald]

My plea seems to be falling upon stony ground
I shall have to get a new one made I fear. Can anyone recommend a good, but reasonably priced engineering workshop that might want to take this on?

I did venture to my store shed to see what i had, all i found was a couple of tapered ones, sorry!

[Colin]

My plea seems to be falling upon stony ground
I shall have to get a new one made I fear. Can anyone recommend a good, but reasonably priced engineering workshop that might want to take this on?

I did venture to my store shed to see what i had, all i found was a couple of tapered ones, sorry!

Thanks Ronald. You must have an amazing store to have TWO of these albeit the later type.

[Ronald]

Well, four actually, as there'sone in the recently rebuilt engine, (than was running today) and another in the complete engine that i removed from the car...... i kept it complete to act as some sort of record of how it goes together for the future,..... but with the rebuilt engine being done the way it was, i hope never to have to have it apart again...!!!

[Colin]

i hope never to have to have it apart again...!!!

I agree.
Mine started as a bit of knocking which appeared to come from the rocker box.
After replacing and re-engineering the valves and camshaft etc, the knock was still there. So we looked at the dynamo gears and couplings. These were also quite worn so we replaced those, and reassembled the engine again.
The battery was flat this time so we did a tow start, only to find the clutch was now completely gone. It had been slipping a bit before and i intended to adjust it but this was a complete failure.
Off came the gearbox only to find the clutch assembly was sodden in engine oil.
As a precaution we removed the flywheel. this is where we found the split flange.
A lesson learned was that you cannot tell where a problem is just by listening. We started at the opposite end of the engine!!
Still, there's lots of new parts which will hopefully never go wrong again (well not in my lifetime). the original parts have lasted this long

[Colin]

The saga continues.....
Paul Rogers deserves a real thank you. He managed to source the parralell type flange from a friend of his in New Zealand.
However, he has tested it with a dye kit and found it too has been cracked in the same place as my one (along the edge of the keyway)

It appears that for CV3487, having one made is the only option apart from being stripped down and replacing with the better tapered kind.
I have opted for the latter so i now need to source a replacement crankshaft etc.

Ronald, You sound like the kind of person with at least two under your pillow
Seriously though. Can anyone help please

[Tony Gamble]

Colin

Not sure whether this will be of any use , but worth a try.

Some several months ago a chap in Herne Bay [ not a million miles from you !! ] was advertising a horde of MG M spares including engines , crankshafts etc etc.

His name was John Miller , and I think that as he was getting older [ aren't we all !! ] his family were wanting him to part with this stock he had amassed. I understand that his address is 55 , Grange Road , Herne Bay, Kent and his mobile number is either 07850 188376 or 07850 185376 . I think if you get through it may be either his son or daughter you get.

Anyway. It is worth a try. I understand it may take some time and negotiation to produce anything !

A final thought if all else fails is that I have one or two cranks lying around but they are not over brilliant , and I am considerably further away from you up here in North Yorkshire !

Let me know what happens.

Tony G

[Ian Grace]

Many years ago, I had twelve OHC cranks crack-tested by my NDT section at RAF Brize Norton. They found cracks in all of them - in the corners of the big end journals. My Sergeant explained to me that these cracks were shallow and that they were almost certainly a consequence of the manufacturing process - not of wear and tear. He explained that modern NDT processes are much more advanced than they were 20 years previously, and find cracks in almost anything, and that the most practical way of checking a crank for potentially risky cracks is to suspend it and strike it with a spanner. If it rings with a clear sound, use it. I have applied this principle over subsequent years and never had a crank go on me.

[Colin]

Sorry for the slight delay in replying.
I will certainly try the fellow in Herne Bay and let you know. Thank you Tony.

Ian, I believe the actual fault is on the Flange, not the crankshaft itself. I only need to replace the "rear main journal flange" (as its described in the manual).
My problem has been finding an original parallel type. they seem to be like collecting rocking horse do-da!

Now that I am opting to go for the better tapered type the whole crankshaft must be replaced. I believe it will be better for the car in the long run.
The tapered type became standard fittings a few months after my car came off the production line, so I don't feel i am "modernising" the car, simply putting right a design fault recognised by Morris quite early into the Minor's production.

[Ian Grace]

Colin,

Sorry Colin, I was one step ahead of you. I just wanted to point out that if you needed to find an original tapered crank to replace your early one, don't be put off if you find cracks in its big end journals - it might still be serviveable.

[Colin]

The latest.
Tony, I tried the numbers you gave but one was switched off and the other did not answer. I was going to try again but then remembered Dave Cooksey, who had invited me to call him at the vscc driving tests recently. He has a spare, so i shall collect it from him next week.

I now have the engine out and stripped down, so after preparing and reassembling it should be good for the VSCC light car Welsh in Llandrindod Wells (fingers crossed) Mind you, the car's been off the road so long i hope the tyres havent perished

[RLucke]

When I was faced with having a new crankshaft made, I contacted Phoenix Cranks. At that time they were offering new cranks and rear flanges to fit our cars. I am sure that they would be able to produce a new rear flange like the original, of superb quality. To use the original crank would be cheaper than the £600 I paid to have my old rods re-metaled and the whole lot rebalanced to fit the new crank.
Phoenix Design and Engineering Ltd
37 The Business Village, Wexham Road,
Slough, Berkshire,
SL2 5EJ,