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MG Midget and Sprite Technical - Sticking clutch

Having just bought back my midget that I fully restored in 1989 I have encountered an odd problem with the clutch. When the engine is cold the clutch works fine and even on occasions after 5 miles of use the clutch is fine. However when it gets warm the pedal seems to start sticking , causing clutch slip or the clutch to come in with a bang nearly stalling the engine when in traffic or pulling away from a junction. It is fitted with an early 90's Frontline Toyota gearbox and a now very noisey release bearing that frontline tell me is a 2/W40 whatever that means. Anyone got any ideas where to start looking or am I going to have to pull it apart first to find out whats happening and then try to source the broken bits? Thanks in advance for any insights.
Richard


R Lawrence

Sounds to me like the clutch driven plate is sticking on the splined shaft.

Just sounds a simple job to remove the gearbox, clean the splined gearbox shaft, fit new driven plate and clutch release bearing.
Robert (Bob) Midget Turbo

I have been trying to find out the exact spec of the release bearing so I can get the parts together in advance but I've had no luck as yet. Apparently a new AP plate will take around 8 weeks to arrive.
R Lawrence

would the plate sticking on the splined shaft actually make the pedal sticky or should the clutch cover push the slave back as normal so that the pedal feels normal, as mine doesn't?
R Lawrence

When you say sticky do you mean hard to push down
or do you mean pedal fails to return?
Robert (Bob) Midget Turbo

the pedal fails to return as I lift my foot, it takes a couple of seconds to start returning so the clutch comes back in with a bang and will stall the engine if I don't catch it just right. It only happens when the engine warms up.
R Lawrence

Take your point mate

You may want to check that the pedal is free to move and springs in tact, plus the slave cylinder is free.

These would not normally be a problem and thus I suppose the clutch pressure plate would have to be considered.

The original Toyota grearbox release bearing does ride the shaft and I suppose it could stick but again removing the gearbox is necessary to check action

I do feel that having a noisy bearing means the box has to be removed so why not just get it done?

My car has the Toyota box that was fitted in early 90s and I have recently changed the clutch to a 7.5 inch so in my garage somewhere is the original bearing, I will ty to find it and see what number if any it is.
Robert (Bob) Midget Turbo

you are right of course, the only way to fix it is get the engine out. I really just wanted to make sure I wasn't missing anything obvious. Think I might fit a rear crank seal conversion at the same time, any recommendations?
R Lawrence

Richard,

You mentioned the thrust bearing. I saw a couple of NOS carbon bearings on EBAY yesterday. The proper branded ones in old boxes.

Sorry can't remember where, but they were def' there. worth a search.
Lawrence Slater

Do the hydraulics have flexible tube? Could be collapsing when warm preventing the return of fluid?
Tim
T Dafforn

I don't think the original thrust bearings will fit the Toyota box although I could be wrong it is 20 years since I last saw it!. I'll check the the lines although I'm pretty sure most of it is copper.
R Lawrence

flexihose?
Nigel Atkins

Just had a look and there is no flexi hose on the clutch it's all copper from master cylinder right down to the slave, no kinks in the copper so it can't be that.
R Lawrence

Is yours a 1275 g/box?

if so here are a couple of ebay links to decent carbon release bearings.

http://tinyurl.com/c6bcbjf

http://www.ebay.co.uk/itm/120916334661?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649



Lawrence Slater

I think the gearbox is Toyota Lawrence, just a guess on my part! :)
Bob Turbo Midget England

...and neither of those bearings are listed as 1275.
Dave O'Neill2

Could the release fork be partially seizing on its pivot, exacerbated by the bearing riding the shaft as Bob mentions. Once again, engine out to fix.

Bernie.
b higginson

That's the trouble with fiting a Type 9. You forget what fits what, and all about other troubles, becuase nothing ever goes wrong with it. :). Sounds like the toyota conversion is almost as good. :P

Well if anyone with a 1098 and box is reading, the carbons will be good for them.
Lawrence Slater

apologies to Tim as I posted same as he had before me

could the fluid be old and effected when warmed up?

does sound more like fork/bearing/clutch issue though
Nigel Atkins

I am almost certain it's an engine out job, I'll report back when I know more.
R Lawrence

had to take it to someone to remove the engine as I don't have the space to store it at the moment. Clutch is currently at AP Racing being refurbished apparently.
RIchard Lawrence

Since it is likely to be an engine out job and you therefore have nothing to loose, you could try spraying the input shaft in the vicinity of the release bearing with a degreasing fluid or penetrating oil. If it is the driven plate sticking on the shaft because of a build up of gunge this may just clear it. Use one of those thin spray extension straws and direct it liberally via the inspection holes in the bellhousing.

Sounds drastic, but I have cured a noisy release bearing this way, which was squealing terribly after repeatedly having to drive through floods a few years ago. Don't worry about the fluid as it will rapidly evaporate off (don't use an oil or teflon based based one!)

As I say, nothing to loose!
Guy Weller

already in pieces Guy...
David Smith

Yes, spotted that, somewhat belatedly! I had read the earlier messages from May but skipped the crucial detail in the one today!
Guy Weller

This thread was discussed between 21/05/2012 and 13/06/2012

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