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MG Midget and Sprite Technical - Ford concentric clutch adapter

I have opened this separate thread to make it easy to find when searching for any info on the cylinder that Guy has used and had some difficulty finding an easy connection.

The concentric unit for Ford Mondeo and other types has a 10mm and an 8mm thread in its casting. 10mm supply from master and the 8mm is used to fit the bleed nipple on an especially long threaded nipple body.

The nipple unit is not long enough to reach outside the Morris Minor Centre supplied A series bell housing used for my engine. So another answer is needed.

I had difficulty finding an easy fix myself, neither ebay or my local hydraulics or pneumatics suppliers could do it. I needed to be able to extend the bleed nipple to outside the bell housing as in my old system.

I decided to modify a 10mm brake pipe tube nut by skimming it down on the lathe to 8mm and cutting a new thread. I wasn't even able to locate a diesel engine spill pipe end such as Guy used so "drastic" was my only possible answer.

I was wary about whether the pipe flare would stop it going into the 8mm thread, but a little light fettling with a sandpaper strip made it an easy fit without hacking too much metal away.

So here is what we got

First, my own futile attempt to make a decent bubble flare with a cheapo ebay tool, didn't work but this picture does show both pipes in the cylinder. The real pipe was made for me this morning locally with nice bubble ends. Yee hah!

You can see that the bleed unit is very deep inside the hole due to bad bubble making but at least the connections are shown.

My adapter plate is in the background, stage left ;)

Bill1

This is the new pipe with its home made nut ready to be inserted in the bleed hole.

Just a gentle sanding has slightly removed the edge that brake pipe flaring puts on the "bubble" so it can drop into the hole.

The thread was cut with a fairly cheap metric tap and die set, I am pleased with the thread it cut for me.

Bill1

Finger tight in the thread, as you can see there is plenty of "bubble" to squeeze shut when the nut is tightened.

Off to search the interweb to find better intructions for using the cheapo tool I have on my shelf, or it will be a gift to the next p*key scrapman to drive up my road.

I am drilling the adapter plate next so the concentric clutch can be refitted to the gearbox.

I'll put that back in the other thread, this is intended to sit in t'archives quietly unless someone needs it.

Bill1

Now that, Bill, is what I would call a very neat solution! Very tidy!

Duly filed away in the memory cells for when I next have my gearbox out.
Guy W

Yes but no but

Your solution was available to you, works and is fine.

I just couldn't find a suitable banjo, the chap who skimmed my cylinder head gave me a length of spill pipe with banjos but couldn't find a small enough one to seal off with small copper washers.

It was steel pipe too so a far less GOOD fix than yours.

This seems to be OK, we'll find out when I stuff the head back on next week and bung her back together.

This idea may help anyone else going down this route though.

Just needs a quick skim on the lathe/a lathe and a careful cut with an 8mm die.
Bill1

Fitted unit all connections tight.

On the left fluid in.
To the right bleed pipe out.

And concentric fitted to gearbox ring and all Loctite and RTV'ed to suit.


Tidier access holes are advised, but the direct 8mm pipe nut needs more space than Guy Weller's tidy banjo fitment. A drawback I hadn't considered.

:(



Bill1

:(

Tidier access holes WERE required as the nuts couldn't be properly tightened up as they were.

I have hacked brutally away at the MMC cast bell housing

(fortunately on the thickest part of my casting)

And now have overhead access to the nuts.

BFH and sharp chisel did the trick as there is no way I was going to add tons of extra ally dust to my garage again.


Blurry picture, sorry, shows the entire Ford unit inside the bellhousing after closing it all up. Nice position relative the pressure plate I think.


The grey-black device bottom left is the A series clutch lever bellows used to keep road muck out of the unit. I need another to close the offside hole too.

laters

Bill1

I bought a pipe-flaring kit from Machine M*rt.

It chewed up the pipe where it gripped it and I couldn't get the flares concentric.

I took it back!

I also received a Sykes Pickavant flaring kit from a deceased estate. Very nice piece of kit.
Dave O'Neill2

My Ebayed device is probably like the MM one Dave, absolute crapomundo.

But the Sykes Pickavant one, now you are talking. Lovely kit.
Bill1

I'm on iteration 2 now

The Ford cylinder I bought doesnt seem to want to operate like the Sayab one did

I measured it to sit against the fingers loosely but that doesnt ahve any extra "push" in it and the actual unit may have been broken when I let the head "lean" heavily on it within the chaos that is my workbench.

Anyway, it doesn't work and if I push it in to get some purchase against the bearing it doesn't compress with a puff of compressed air like the old one would.

Reading Guy's definitive work on the Ford unit again I think I needed to allow quite a lot of pressure against the fingers of the pressure plate before the clutch operates, Guy can you confirm this (or not, of course) please?

John Collins has supplied me with a concentric from (we believe) a Granada which has more "nose" to it and when I fit that the bearing runs deep on the fingers with about a quuarter of an inch of unused movement. My feeling is thatif I reduce the carrier thickness by another eighth or three sixteenths of an inch (Sorry my old head works bettererer in Imperious measurings) I should still have enough movement within the cylinder to use for the clutch operation

I dont want to close her up again then find I'm deeply in a fail cycle.

Anyone with idess to help please join in

Here is the cylinder in the hole with the spare play highlighted with a screwdriver, I think if I can get double that and still have movement when the hydraulics start working it should work fine.


What a to do

Bill1

Hi Bill,
I am struggling to understand your problem - other than the bit about it not working!

As far as I recall, the thrust bearing on the Ford unit moves back and forth along a built in "guide nose". I think I worked on the theory that when fully thrust forward I didn't want it to fall off the end of the guide. Whilst at the other extreme I wanted to be sure that when fully retracted there was still some clearance to allow for future clutch plate wear.

So, as installed the thrust bearing is pushed fairly well back along the guide tube. Then, when operated from this position it moves forward by, as far as I can remember, about 12mm (? somewhere I will have some scruffy notes where I will have recorded that.

The other thing to watch for is that the guide extends past the end of the fingers, into the depths of the clutch cover. But not so far that it fouls on the driven plate or other rotating gubbins therein.

Does this photo help at all? It looks to me as if my bellows are more compressed than yours in the "stand easy" position.

Guy W

Thanks for that Guy

So as I understand it, you do use up some of the bellows squeeze with the cylinder partially inside the hole.

I have approximately 5mm unused so if I get myself another 5 or 10 I should be sorted then?

The Granada cylinder has some drawbacks and some more things in its favour.

major drawback for we budgeteers £99 or thereabouts

benefits though are massive, it has a longer bleed nipple bolt/screw/doohdah and will easily be reachable from outside the bellhousing if a careful note is made and a decent size hole simply drilled through and the inlet pipe hole is at the bottom so feed can be through the old pivot lever hole.

In the picture that is the in pipe on the left and the bleed screw fits into the itemn on the right from the face angled to the bottom right, which takes it straight to the edge of the bellhousing through the top viewing hole

SO I dont really NEED the remote bleed screw now After all that fuss :(





Bill1

The pi8ece of bent solder wire shows the distance from the clutch fingers to the back of the concentric, at the support unit face

SO I have plenty of room for reduction of the support's thickness, this cylinder moves smoothly in and out, my other one jerks and shudders its way through a much shorter distance.

I will aim to get about half the bellows closed when I fit it then, thanks for that useful info Guy

Ceers

Bill1

My logic Bill, was that the start position of the bearing needs to be almost fully retracted. But not so much that a) there is no further potential movement to allow for clutch plate wear, or
2)that the "nose" end of the guide tube fouls in whirling bits inside the clutch cover.

The actual movement needed is somewhere around 11 or 12mm (1/2" ish). So anything more than that is irrelevant at best, and at worst might result in overthrow. I think what I did was machine the mounting block to a dimension that held the thrust bearing compressed back from its full extension by around 12mm.

Still haven't unearthed those notes though! Sorry!

Guy W

I have :)

I'll email them back to you , shall I? (YES I WILL, see inbox soon)

The thickness you used was 43mm.

I would use similar but my Mondeo unit seems faulty to me and only seems to have about 1/2" movement in it.

The thin lip on the inner guide tube end is slightly distorted too.

The Granny one seems pretty good in comparison and has a huge amount of available throw

So shall I fit it so the spring is pressed back quite a long way? As it is there is only one "concertina" compressed, go for a few more shall I?

Bill1

Something else I noticed when running a rule across the granny bearing face is that it has a slight convex curve

Which may well help me get a smoother ride
Bill1

OK maybe a last update for this job.

Mine is in with the Granada concentric, pushed back along the slide so there is about 12mm of forward movement to operate the clutch.

We reckon that should be enough to prevent possible overthrow and clutch destruction.

I'll let you know how that went later, on the French leave topic.
Bill1

Logically, the amount it moves forward is dependant on the amount of fluid displaced by a single clutch pedal stroke, together with the physical proportions of the chosen slave cylinder. When I did mine I couldn't find any data on this so mocked it up and tested to see how far the slave thrust bearing would move. I was pleasantly surprised that it was about the right distance as it was. But then maybe all clutches need to release by much the same amount - 12 mm or so. Had it travelled too far, I would have added an adjustable stop under the pedal, rather than relying on the available length of the slide guide to limit it.
Guy W

I gave it a hearty blow from my compressor and it wouldn't go past the slider limits so I reckon it'll do for me.

Soon find out again :(
Bill1

should be ok. But if you imagine the release bearing coming up against a solid stop when the pedal was still only part way down, and you kept pressing your hoof on it, then that pressure is going to eventually escape. Or do some damage in looking for an exit.

The limit to how far the thrust moves needs to be either because the system design matches the volume of fluid moved by the m/c matches to the amount required at the other end. Or because the pedal has a stop to prevent pushing too much fluid down through the pipes.

By some good fortune, the master and slave system volumes do seem to work out correctly matched so I don't think it would be a problem in practice.
Guy W

Well, the car is running but there are signs that there is still a certain amount of air trapped somewhere.

Pumping the pedal several times got me pressure enough to drive the car back into the garage though.

I may have to live with a slightly lower pedal operating height though, we'll know after I rebleed the slave again. It isn't much of a drawback.

Hoping to get an MOT appointment and new tax tomorrow, finger crossing time chapses.

Some minor water leaking too, but I'm not in the mood to have a look tonight, 'tisn't as if I need the car desperately for a day or two.
Bill1

You'll need it on Saturday, don't forget.
frogeye Gary

May be using the Monjo on Saturday Gary, all depends on logistics for now

see you there
Bill1

Bill,
I would leave overnight and then bleed again. Or better, go for a drive to shake the bubbles out, then bleed again. If it is drivable as it is!

Mine self-bleeds. I mean that all I need do to bleed any air out is to crack the bleed nipple open and the fluid feeds through under gravity. It doesn't even need the pedal to be pumped. That is, once the initial filling of the system has been done.

Easiest bleeding system I have ever come across!
Guy W

I do hope it isn't that end-stop on the Granada slave that is preventing your clutch thrust bearing from moving far enough forward to fully disengaging the clutch.
Guy W

No Guy, not the end stop I think

I can engage the whole range of gears when the pedal is working and she was fine to drive into the garage

I will be rebleeding a little, but need some more DOT4, I lost lots when the bad pipework reared its ugly head

:(

With luck I will be using it on Saturday - after using it tomorrow if I can get the MOT arranged at short notice

Should be OK I think, I may even try your bleed system when I'm sure all the nooking crannies are full.

Not much worried, the car started nicely today, but on 13 thou tappets. Need to reset them too.

Minor wtaer leaks worry me more than the new clutch and she's always lost a a little H2O for years.
Bill1

Ah well, that's good. Sorry to cast doubts!
I guess if the slave end stop was coming into play you would feel the pedal go solid before it went to the floor.

Do you know where the water is going, or is that a mystery yet to unfold?
Guy W

Good to hear she is nearly sorted, Bill.
Good luck with the MOT, but I don't think you will need it, I can't imagine you would take her in if she wouldn't pass.
Dave
Dave Brown

Due to other commitments today she is not getting MOTed til next week, probably Tuesday. Then to the Post Office for an RFL.

But I am relieved to note that although there is still apparently a little very recalcitrant air hiding somewhere the clutch works just fine. Good control and feels a bit lighter than the Sayab unit did too.

W I N !

Spent today fettling, as ye do, and fitting new motorcycle type bulb holders to the manky reversing light and resistance barrier units (eg connectors)

Now happy to report both reversers work again at last.

Timing was set and base idle adjusted too, no apparent water leaks so what I found in the garage drip tray last night was likely to be loose water from flat surfaces dripping off.

Dave, true except...

I do like to allow my MOT man free rein to give me advisories, it's well worth the £30/£40 to have advance warning of future "items"

My MOT guy found some hidden rot behind the rear spring front mounting once, I couldn't see it but he may have saved my car by probing around "below stairs" that day a couple of years ago.

I'm glad Lara is not old enough to get a free pass from MOTs
Bill1

Bill a bit late but do you want me to bring my Easybleed tomorrow?
frogeye Gary

Hi Gary, no thanks mate I have me own.

Something about the clutch's pipe configuration and poor seal performance of my reservoir seal is likely to be all I need to address. New bottle of Halfords DOT4 next Tuesday will sort it all. I have some new lid seals in the garage.

See you tomorrow.
Bill1

Well as the original French Leave threads have archived I may as well use this to close the circle.

MOT today, and passed. So off to Post Office for a tax disc (twice because I was given duff info by a girl in Swansea vis a vis coming off SORN...) and having just driven about fifteen miles I can declare that the Granada concentric has resolved my problems

As I thought the slight radius across the bearing face made the pedal easier to use, probably due to a different master cylinder bore too.

Lovely control and the airbubble seems to have dissipated, maybe back up the down pipe and into the reservoir.

The gearbox sounded a tad harsh and when I dropped the drain plug out no oil came out.

oops

So I have put a litre and a third into the box and tomorrow I will se if she's a tad quieter with wet oily gears. (Comma 75-90, should be better than no oil I reckon)

I am very happy with the engine, idling around 800rpm with little stuttering and with excellent pick up under throttle.

Minor engine oil leak from the capillary pipe junction, an extra tweak on the small hose clip has sorted that.

I will pop a picture here tomorrow of the damage to the concentric's nose tube caused when the unit came loose and wore against the clutch bearing.

The bearing was severely damaged too.

Lesson~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Use PLENTY of Loctite when bolting the innards in

Lesson learnt this time around, phew.

Bill1

Sounding very good then Bill. Well done!

Remind me, what did you do about a replacement clutch plate. I thought the last I saw was hat you were going to check the clutch cover for clearance around an "off the shelf" plate.
Guy W

It's in there somewhere Guy

I gave up trying very hard to find a "offdapegone" and popped down to MMC for one of theirs.

If anyone needs it I can find the phone number for the chap down in the West Country who was prepared to make one up for me. Or the guy who wanted my dead parts back to use in cannibalising one up (£70++)

All came in just under the MMC price and I have a big comeback if MMC's fails in a silly manner, hence the decision to shop at Oldbury.
Bill1

OK, so MMC is the winner then.
Guy W

Well done Bill

if you've already got the Comma stuff fair enough but I swapped from Comma 75/90 semi after only 2 years and got an instant improvement in gear change, in a warm April too (ever better for the colder weather) by using Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF (GL-4)

no one has followed my lead so there's only my word for it but I had enough trouble with my g/box conversion to know any improvements

for illustration only - http://www.opieoils.co.uk/p-739-castrol-syntrans-multivehicle-75w-90-fully-synthetic-mtf-replaces-smx-s-75w-85.aspx

Halfords do it too - http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_209375_langId_-1_categoryId_255220


Nigel Atkins

Cheers Nigel, I remember you swapping but as I had a couple of unused bottles - and a dry gearbox I thought it the better of two options.

I may change later if this doesn't work out, but the Comma stuff has been ok before.
Bill1

no problem Bill, Comma stuff was fine in the box just that the Castrol stuff is better

and as you say the Comma is better than running dry, nice to know even the experts make schoolboy errors, yesterday my wife's mate put a slightly wrong size washer in a fitting that was very awkward and very slow to get at, confirmed when it leaked and had to be taken apart and all redone at great length
Nigel Atkins

A bit of forensic work on the old concentric shows this

11mm of forward movement along the centre stem to operate the clutch

And the beginnings of some nose wear at the right hand side of the picture

Remember the concentric worked loose inside the bell housing and allowed the clutch driven plate to run twisted and eventually separate from the spline unit

This picture shows the wear markings on one (the less affected) side of the unit

Bill1

As you see the actual clutch control work is done with the main seal at the base of the tube, 11mm of movement tallies nicely with the calculating that Guy and I thought we'd need.

The hydraulic effort is concentrated at the base of the tube by pressing the centre bearing carrier forwards when the pedal is used. Funnily enough there is nothing wrong with the carrier component, wonder if there's a market for old ones? eBay beckons purrups...

Anyway, this next picture shows the horrendous damage letting a concentric run off centre can do to its bits.

The damage was caused by running inside the fingers of the diaphragm, but off centre.

The release bearing's spring loaded carrier plate wore away quite drastically.

Almost unbelievably the clutch cover survived this without any apparent damage.

We'll see whether I should have "failed" the component over the forthcoming months if it fails me. I think it will be fine.


Ho hum, "whistles and wanders off"

Bill1

Interesting photos Bill.

Soon, but I am not sure when, as "soon" has a variable timescale definition, I will take my engine out for some refreshing and will get a chance to investigate how my concentric is bearing up.(pun) I wonder if it will show similar wear marks. I presume only if the home made carrier block, or the concentric itself, has worked loose and has had a a little jiggle around.
But as yet there is no external indication that this is happening. Were there any symptoms of this condition on yours before you stripped it down?
Guy W

Well yes there were Guy

Driving down through France in June the clutch started a kind of tramping dance, not as awful as the old tramping the external fork gave me, but a definite dancing feeling

Sometimes went away but as I reached Le Mans camp site safely I parked up and kindly allowed young Gary to ferry me about over the weekend. It was OK going home, occasional bumping and grinding until I was passing Lisieux then bang.



Bill1

Ah, so I surmise that so long as I don't go to Le Mans, and specifically don't go anywhere near Lisieux, then mine should be Ok.

Or am I drawing the wrong conclusions from your experience?
Guy W

LOL


could be...

If I had not gone to our traditional Normandy spa watering hole after the race I suspect I'd have made it to the ferry

But we always indulge after most of a week under canvas (so to speak) with a few hot showers and a fine dining experience at the Cafe de Paris, then after our fill of a variety of French beverages we sleep in soft downy beds for one night.

I would expect YOUR concentric to have been better engineered than my Sayab lash up.

So not an issue ;)
Bill1

"so I surmise that so long as I don't go to Le Mans"

Guy, dont think thats it, i think its Gary's presence...
He was with Bill in France and then Bill couldnt operate his gearbox anymore...
Just like when Gary was on Llandow racetrack previous summer when Gary's own gearbox couldnt be operated anymore...

Gary and the gearbox-gods must have some issue's for what theyve jinxed him and everybody arround him...

superstition in the classic car world?
Never heard of that! ;)

Arie de Best

I don't understand it with my own gearbox at Llandow. All I did was hit the brakes hard and then change down from 5th to 2nd at the end of the pit straight to flick the rear of the car around the hairpin, therefore saving the strain on 4th and 3rd gears and after 10 or so years of doing this on trackdays and sprints, the damn thing let me down. I'm going to write a strong letter to Datsun.
Concentric, schmoncentric!
frogeye Gary

So if I stop using second after top my box will be fine...

Ah well, that's good news :)

Guy I was promising myself I'd "refresh" the engine for the last three winters but never got round to it.

I wish I had now, I might have noticed the unit working loose.

Bill1

Yes, I am on Winter 2 of my refresh programme.
First step is to stop using it, but I am struggling with that stage.
Guy W

Had my concentric Mondeo unit for 6 years now and no issues even with 360bhp. Got over the wierd thread issue with braided hoses.

J L HEAP

Taking the motor out again soon so can measure up free play and general positioning if it will help.

J L HEAP

Interesting. Looks like it's an adapter that resolved the thread size issue, 'though I like the use of braided hoses too.

Why did you drill extra holes for the braided hoses when there is a big gaping inspection hole right next to them?
Guy W

The clutch lever hole is pretty well blanked off when installed in a Minor, the two holes were also better positioned to reduce both the amount of pipework inside the bell housing and provide better 'runs'for bleed and feed. The top slot is to clear the steering rack , but offers no space for exiting pipework. This bell housing was to be modified to fit the stronger T5 gearbox as the motor was destroying type 9's.Pic of new set up below.

J L HEAP

Nice looking assembly. I thought there must be a good reason!
Guy W

Has this wee beauty in front of the box

J L HEAP

That looks rather good JL.

I wondered if there'd be a braided option for the 8mm thread somewhere but just couldn't locate one easily.

Which is all a bit over the top now as I am able to reach the Ford Bleed Screw assembly at the top of the bellhousing now. No need for special anythings now the bellhousing has been opened out at the top.

Funny how things work out.

I'm glad you posted the pictures in here though, it will all be "findable" in the BBS tech archives this way.

Thanks

Err, maybe I should remember but cannot. What engine is that beauty?
Bill1

The motor shown is the entry level standard 2.0L black top Zetec with Rotrex supercharger. About 220bhp and 200ftlbs of torque. Coming out this winter for an upgrade to a reliable 300bhp, good fun in a 800 kilo Minor.

J L HEAP

oh nice

'twas the supercharger bit that threw me then
(he lied) thanks

:)
Bill1

Don't moggies have such relatively spacious engine bays, when compared to Spridgets! Pity Spridget engine bays weren't bigger. But if they were, they would probably have been called MGB's.
Lawrence Slater

The minor chassis legs are pretty close Lawrence unfortunately, but above these, there is a reasonable amount of room. However the Minor engine bay is very short resulting in cramming components in or moving them to different parts of the car.Most big modern motors , ie K or Zetec require a high degree of bulkhead modification. Hopefullly our development of the 1.0L 3 cyl Ecoboost engine will enable it to be fitted with minimal modification even in A 30 or 35's.
J L HEAP

ooohhh, tread drift, thread drift,

we've had a few small 3 cylinder engined cars (largest 1.0 litre) and really like them

- but -

J, you got any photos of slightly modded A30/A35 to put up

I was thinking only yesterday of a 1275 A35 saloon we saw a while back and how I could see myself with something similar in the fleet when the numbers come up
Nigel Atkins

Not yet I'm afraid Nigel, but we will start a commission next year on an A35 Ecoboost.
J L HEAP

nice!
Nigel Atkins

This thread was discussed between 21/09/2013 and 30/10/2013

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