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MG Midget and Sprite Technical - Broken clutch

Out in the Sprite for the first time this year and blowing the cobwebs away on the motorway at about 70mph in 5th gear ('65 1098 with type9) there was a muffled bang. I thought that something had been thrown up and hit the car, or had I left something under the bonnet after the service I'd just completed?
When I left the motorway I stopped at a traffic light and found it difficult to engage gears. It got worse until I got home and couldn't select reverse to get into the garage. Switched off, engaged reverse, started the engine and experienced severe clutch drag.
Jacked it up to have a look. No fluid leaks, but looking through the bell housing from the side I could see that the release bearing seemed to have a bit of carbon missing. so that's what I think the bang was.
OK. Engine will have to come out etc. My question is, has anyone got a 1098 with a type9 using the standard 1098 clutch as I have, but with a roller release bearing? (I don't want to put another carbon thrust in). Will I need a 1275 fork and are there any other mods to do?
I will bleed the clutch on Monday just in case it's that, but I'm not hopeful.

Thanks as always.
Bernie.
b higginson

I just re- read my post and it looks like I was asking to buy a 1098 with a type9. I'm not, I just wanted to know if anyone has done it using a standard clutch but with a roller release bearing and was it successful? Sorry for the confusion.

Bernie.
b higginson

Bernie,
muffled bang, bit of carbon missing - I don't think you need to look at bleeding the clutch for this answer

there have been many reports of poor quality carbon release bearings

when I had trouble with my l*ing b*stards 'specialist experts' type 9 installation on my 1275 in the end the release arm broke because of the poor design of my installation and I now have an MGA competition release bearing fitted

a video here to show, especially at the end, how much abuse and wear the standard release bearings can take - http://www.youtube.com/watch?v=d173K60GSU8&list=UU40j4KqUJPMVv4FQ29ro-xQ&feature=c4-overview



Nigel Atkins

Thanks Nigel.
I already do as Mr Twist says, ie only use the clutch for moving off and changing gears, because of the fragility of the carbon thrust bearing.
Mine has been in for about 6000 miles of non-abusive motoring, I had renewed it when I fitted the type 9, so maybe I got one of the poor quality ones.
I'm only going to check the hydraulics as a belt and braces measure, just to make sure everything is OK in that department first, but as you say, I think I already know that the engine will have to come out.
I was just wondering if anyone had done the roller bearing thing on a 1098 with a type 9.
I believe Peter May sell roller bearings so that's my next port of call.

Bernie.
b higginson

Bernie,
I'm pretty sure (not certain with my memory) that some have used roller bearing with a type 9 but not sure about with a 1098

good idea to check hydraulics anyway just to check them

also see if the slave pin or release arm are going too far/not far enough as appropriate

I'm the same with thinking I should renew associated parts whilst at it only to find the old parts were fine but the new parts are rubbish

I put in the JT vid for the end part where it shows just how much abuse the carbon thrust bearing and/or clutch can take and still continue to work

I think the bad carbon thrust bearing have a rolled pin in the surround

see 'Update April 2008' on page link below - Paul's site is for the B but obviously a lot of information is relevant to Spridgets if only in principle

(clink on photos to expand them) - http://www.mgb-stuff.org.uk/clutchtext.htm#release
Nigel Atkins

Bernie
Can I e-mail you?
Alan
Alan Anstead

I cant imagine there being an issue with the 1098, but my names not jesus christ ither

Look back about a month or 2, someone sourced a roller bearing for his ride...and got it togather recently... I cant remember his name

Id also check with alan (amstead ???).../he seems to know a thing or 2 on this topic

Peter may engineering advertises a roller bearing also and I want to say JHL who comes here time to time has the parts also, might give mark T a shout down in the land down under....he would know what works and can put togather a kit for you, im not sure if he would charge the same as a vegimite sandwhich...hahaha

That sucks bernie.....but at least you and the car got home okay.

Prop

Prop and the Blackhole Midget

Bad luck Bernie, I too had a sh##ty carbon thrust bearing which totally disintegrated and has been replaced with a Peter May roller bearing on a 1275 with standard box.
I thought problems over but currently can only drive 8 miles or so before gear selection becomes impossible - it may be hydraulics although they've been bled several times using the techniques in the archives (most effective seems to be clamping the slave cylinder piston) so give it one more try before the engine comes out...
Hope you get yours sorted and be grateful if you post the results.
Jeremy
J Tickle

I won't be in the garage until tomorrow so I won't know if there are any other problems inside the clutch like broken springs, driven plate faults etc but I will report back and will also post pictures.

Alan. Please feel free to email me at above address. Your advice is always welcome.

Bernie.
b higginson

I got the engine and 'box out yesterday and what I found was the bush in the clutch fork had become oval, allowing sideways movement of the fork and the bearing to engage not square to the clutch pad.
I'll try to upload some pictures.
First the fork.

Bernie.


b higginson

And the result.


b higginson

Getting the engine and box out was a pain because of the length of the Ford box, so to avoid a repetition I'm going to fit a roller release bearing (When I can find one). Neither Peter May nor AP Racing do one for the 1098 engine, so I've contacted this guy http://www.spriteparts.com.au/ It's a long way and not cheap but I really do not want to drag the engine out again. He makes them using original castings and fitting a roller bearing in place of the carbon. Check out item 171152523876 on ebay.
I'm also going to replace the other parts of the clutch and have a look at the hydraulics.

More later.

Bernie.
b higginson

Bernie,
This may, or may not, apply to your case. But there was a design fault on the early T9 conversion kits. Installation involves cutting the tubular guide (AKA nosepiece) off that surrounds the front of the T9 input shaft, and this was used in combination with a fixed pivot point for the clutch release fork.

The result of this arrangement was that the clutch fork has a fixed pivot and operates through an arc as the release bearing doesn't have a guide tube for it to slide along. The release bearing cannot therefore be truly concentric with the clutch cover at all times as it moves back and forth along the axis of the car. Combined with this either worn fork bush, or lateral slack in the bush mounting pin that allows the clutch fork to droop down and accentuates the wear. In severe cases this also creates a lot of noise as the clutch release bearing nods and bounces around on the rotating input shaft.

I believe that later T9 conversions used a modified pivot arrangement that had an extra link in it and this allowed the clutch release to move parallel with the input shaft, rather than in an arc. I don't know if that solved the problem completely. It was for these reasons that I modified mine and installed a concentric slave cylinder arrangement.

Guy W

Bernie that is why I installed a concentric too

The eccentric motion caused me to have a couple of broken diaphragms on my 1275 type clutch cover

The clutch was "tramping" as I used it, kicking back and releasing on every rotation of the flywheel

I hope you can get sorted with the new roller release

The Ford roller sits in the fork and is held by a sliding springy device that allows for the eccentricity by moving to stay centralised along the guide tube
Bill1

Guy, Bill. No noise until the day the bearing broke up, no clutch judder. My bellhousing from Morris Minor Centre only has one pivot point so must be an early one. I cut off all the tube. Does fitting a concentric slave need the tube. The reason I've sort of shied away from fitting one is that before I retired I had worked on various Fords with concentrics and when the bearing or slave failed you had to replace the lot, which on a Spridget involves engine removal. I haven't ordered a roller bearing yet, so I'm open to persuasion. My clutch is not a diaphragm so I wonder if it's suitable for a concentric.

Bernie.
b higginson

Not sure about others, but my Ford-based DIY installation of concentric slave doesn't use the original guide tube. I had already cut that off when I first installed the T9 with the MMC style clutch release arm (like yours). The ford concentric has its own built in guide.
You are right about replacement needing engine out. In fact any slave work other than bleeding would need the engine to be removed, so that is a down side. But so far mine has been trouble free since around 2006 and around 45,000 miles. No doubt though that I will replace the slave unit when I need to replace the clutch itself, and that will cost more than replacing a roller thrust bearing would. (Ford unit cost me £28 in 2006)
Guy W

Bernie the concentric has what is basically its own tube

There are lots of photos in the BBS M&S tech archive under concentric, here's a picture from one of them

The flat(ish) face is the bearing as you will know


Bill1

Bernie,
if the photo below isn't relevant to you then ignore it

despite my type-9 installation being done in October '09 it was not to the L*ing B*stard 'specialist experts' own specification and was a mongrel probably put together out of what was left from stock/other jobs/old stock

the measurement being checked didn't comply

also notice the broken arm (washers had already been added for better location to the pivot of the arm)


Nigel Atkins

Nigel. Your installation looks similar to mine except yours is 1275 as against my 1098.
In favour of a roller bearing is in the event of a slave cylinder failure it can be changed without removing the engine. Not possible with a concentric. However, Guy and Bill's reports of ultra reliabilty withe the concentric makes a good case for that route. Decisions!

Bernie.
b higginson

Nigel,
Yours has the later style sliding pivot point that allows the fork arm to move laterally and therefore the system retains the original release bearing guide tube. The 4 washers either side of the pivot are to allow the pivot to slide, whilst minimising any tendency to drop. It may be broken as well, - I cannot see from the photo, but the two pairs of washers are part of that designed system which was intended to get around the failings of the earlier configuration.

I don't now have a photo of the original version,(yes I do, photo next post) the pivot was different to yours and it also entailed cutting off the guide tube which then resulted in problems of keeping the release bearing co-centric with the clutch.

Yours also looks like it has the longer input shaft which would normally need shortening by 20mm for an A- series installation. But again, I'm not sure about that just from looking at a photo.
Guy W

The type 1 pivot was a simple device!


Guy W

And the guide tube was cut off on the earlier versions. Compare this to Nigel's photo.


Guy W

And whilst I have found my photo file - here is my concentric arrangement that I replace the earlier "official" T9 arrangement with, because of the design problems.
The slave has its own built-in guide tube.


Guy W

Hi Bernie,
just got some bits for the Frog from Moss and noticed they had a roller bearing conversion for MGB's.
Unfortunately, I completely forgot to ask about midgets for you until I was in the car on the way home. DOH!!

Might be worth asking Moss? Although if they do do it, it would probably be cheaper getting one shipped over from Aus.

Rob
Rob aka MG Moneypit

Guy,
I can't remember the details now but the installation I had done by the L*ing B*stards 'specialist experts' did not match their (then) current specifications, the measure is there to show that it didn't match

IIRC those washers shown in that photo weren't there at initial installation, what was there before I can't remember now and I didn't retain all the information because as you can no doubt tell the whole thing p*ssed me off (being on top of their other lies)

if it was the broken arm you couldn't see properly on your screen then this photo shows it better


Nigel Atkins

"No doubt though that I will replace the slave unit when I need to replace the clutch itself -- "

Guy, wouldn't you just be able to replace the seal (o-ring? ) in the slave, rather than the whole slave?

I'd go for the concentric bernie. I'm not sure how much more it costs than the bellows type, but burton still sell the same type I have in mine.

http://www.burtonpower.com/parts-by-category/transmission-clutch-wheels/clutch-components-hydraulic/hydraulic-clutch-cylinder-nose-apc5.html
Lawrence Slater

Nigel, I wasn't really commenting or meaning to comment on the "workmanship" or otherwise of your local friendly specialist! I know you have had issues with their work over an extended period. And I can see the damaged lever arm now you have supplied an enlarged photo.

I was trying to point out for Bernies' benefit, the differences between the early and later designs for the T9 installation, still utilisation the A series lever arm and external slave. The earlier generation installation definitely had problems which resulted in off-centre wear of the release bearings.

Lawrence - "just replace the O ring". Very probably, if that is the only item likely to have warn. I was rather assuming that as the design is of constant contact with the clutch, that the bearing would likely be worn too. I have been in the habit in the past of always replacing release bearings when I do a clutch job, so would normally expect to do so again, with the concentric variety. Although the cost would be higher, I would expect to get at least 60,000 miles plus out of the unit, probably more
Guy W

fair enough Guy but the post was addressed to me so I assumed the last sentence starting >>Yours<< meant me

I realise all posts are also for other viewers

if your last line was aimed at Bernie sorry I misunderstood
Nigel Atkins

Yes Nigel, it was addressed to you as I was commenting on your photo. But I wasn't attempting to defend the work displayed by your installers! Just to say I think the washers are correct for that type of pivot. If they were a late addition, then they had been forgotten first time around which probably fits with your experience of the installers. As this is also an open discussion the purpose of getting involved is because I thought I could add information that might be of help to Bernie wrt his worn release bearing.
Guy W

Guy. It wasn't until yourself and Alan Anstead spoke about a later version of the pivot that I knew there was one. I think I can see in Nigel's last picture that the pivot bolt hole is in fact a slot. Am I correct? If so, do you think I could elongate my hole (ooer missus) to replicate the later version. Of course, I suppose I would have to find another seal housing and tube. What do you think. Is it worth it?

Bernie.
b higginson

Yup I agree with you about replacing the bearing if you are replacing the clutch Guy. But can't you buy the bearing seperately to the slave body? Seems a shame to have to replace the lot, if only the bearing's gone/wearing. On the other hand, at least you'd retain some spares if you bought a complete new slave.

I'm hoping to pull mine in the spring weather(whenever that is) and buy some new o-rings/seals. The bearing for the burton type is £23.89 plus postage. http://www.burtonpower.com/parts-by-category/transmission-clutch-wheels/clutch-components-hydraulic/clutch-release-bearing-for-acp5-carrier-hd4941.html

Not a bad price really, so I think I'll buy one in advance, and keep it as a spare if not needed yet.
Lawrence Slater

Bernie, I ma not sure as I changed mine directly from the poorly performing early type, for a DIY concentric installation. I only later discovered that there was a modified the pivot point arrangement available. It would be easy enough to adapt the early pivot, but it is still an engine out job if it doesn't work right. You need advice from someone who has the later type of pivot.

Lawrence, yes, I might just change the bearing part at that price (£23). But might not be worth messing about with as this is the full part that I used, still at a sensible price of £36
http://tinyurl.com/pph7s5y

Amazed to see what Burton charge for the slave plus mount! £234 !! http://tinyurl.com/prnfbcr

I made the mount for mine from a £5 billet of aluminium. Total installed cost below £40

Guy W

Blimey Guy. Burton do mark it up don't they.

I think you should be awarded the title for the greatest diy saving. Bravo sir. Bravo.

I wonder if the type I've got is cheaper elsewhere too.
Lawrence Slater

Bernie,
I think you are right about the later pivot bolt holes being slots hence the added oversized washers perhaps

I think (not sure) I saw a pdf of the later installation instructions on the web somewhere but sorry I can't remember if and where as I deleted the info I got

my photos here are low resolution so I can't zoom in and enlarge the area to see better with any clarity

perhaps you could ask if anyone has the latest fitting instructions, perhaps as printed paper copy out of the box of the kit from various suppliers

Guy,
we both have the same aim to help Bernie and others just that as normal we can't get on each other's wavelength in our posts
Nigel Atkins

Ever since the beginning of time there have been two schools of thought, and application, when removing engines from Spridgets.
I am of the remove the engine only school (leaving the engine in situ' ) and this still holds good with the T9 conversion.
Another assist used, not by me, but a Spridget racer friend is to modify the engine mounting to chassis brackets.
Where the hole for the rubber mount is in the engine forward mounting bracket the hole is slotted outward. Thus engine removal is done by only undoing the large, lower, nut on the engine rubber mount and lifting the engine away leaving the two engine mount brackets in situ.
Upon reversal the slot allows immediate alignment of the engine.
Am I lucky? 44 years a Sprite owner and I don't have the problems others experience with carbon thrusts.
No problems found or reported with thrusts, be they roller or carbon, fitted to my T9 conversions (or should that be - so far?).
Alan
Alan Anstead

I've delayed reactivating this thread until I had got some mileage under my belt with the new clutch. Well now I have, so here goes.
After all the problems listed above, I fitted a NOS Powertrain clutch cover, NOS Borg&Beck Avenger driven plate and a roller release bearing obtained from spriteparts.com.au

At first everything was OK after a short (5 mile) test run. It was like a modern car with great easy smooth gearshifts. A little later, the new bearing started to "whistle" a bit. Barely audible, bit there nevertheless.
Next, I started to lose "pedal" and experienced baulking. After a 200 mile club run I had virtually no clutch unless I pumped it. I figured that the M/cyl seals were shot and the fluid was just moving to and fro in the clutch master cylinder without actually leaking. This proved to be the case and after renewing all rubbers in both M/cyls (Tandem type) and slave, I inastalled a remote bleed valve half way up the back of the engine.
Everything was again fine on a short test run. However, yesterday, at the end of a 50 mile round trip to a car show I am now getting a different problem. Sometimes I have a perfect clutch, but as things warm up I sometimes get reluctance to engage, but this too will clear and then come back again. No loss of pedal feel was experienced.
I'm wondering if the pilot bearing is going bad and starting to grab the first motion shaft, or do I have selector problems in the 'box? and would fitting a new saddle at the bottom of the lever help?
The release bearing "whistle"is now more audible but not much. You really have to listen for it.
Any thoughts chaps?

Sorry for being so long winded.

Bernie.
b higginson

With regards the whistling..
I replaced a roller release bearing in a Lotus elan a few years ago.. worked great, but always whistled a little..
Never gave a problem
Tim
T Dafforn

Tim. Thanks for the confidence boost. It would appear though that the whistling bearing is the least of my worries. It's not too bad anyway.

Bernie.
b higginson

Hello Bernie
I have the concentric slave cylinder with the rollerbearing in the MGB (Type 9 box) and so far everything is fine and there is no whistling.

I had the same problem as you with the carbon breaking up in the Frogeye, I couldn't find a roller bearing for a Sprite at the time so fitted a new carbon one. Although the bearing remains square to the cover plate, I do get a loss of use on a long run. On the Drive It day run, it was fine until about 10 miles from Llangollen and then I had to pump the pedal, after the trip round the museum, it was fine again but required pumping towards the end of the run. It is possible to bleed air out of the system after a few months despite the seals being fine in the master & slave
Cheers
Mike
M G Bennett

This thread was discussed between 17/01/2014 and 15/05/2014

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.