Thread: Clutch (or lack of)

Sounds as if there is an (unusual) problem with the release fork. Which means removing the box (or engine). Earlier boxes, and I'm not sure if it applies to the S3, removing the bracket that holds the gearshift reveals an opening into the clutch housing, through which you may be able to see what is going on.

This sort of mechanical fialure is unusual - most such failures, as you probably realise, are in the hydraulics, so you need to ensure that the free play on the pushrod at the slave is not the normal movement. As a further check, ensure that the slave cylinder piston does move when you push the pedal down. I would suspect (unless you have already checked this) either the nuts have come loose on the master cylinder pushrod, or the trunnion has worn through.

John

Thanks John I will check out the hydraulics and confirm that slave is definitely working before I pull the gearbox out. Might give it a miss tomorrow though forcast for 40 degrees

Only 40? 41 here!

John

Earlier boxes, and I'm not sure if it applies to the S3, removing the bracket that holds the gearshift reveals an opening into the clutch housing, through which you may be able to see what is going on.



there is a removable plate over the inspection opening under the gear lever bracket in the series 3.
cheers,
D

Some of the thrust bearing carriers on Series 3's are plastic.
I think they are an aftermarket part.
If your vehicle has one it may have deteriorated and fallen to bits when you clutched.

Cheers, Mick.

Originally Posted by Ben_Burdett

Hi guys my series 3 all of a sudden has lost its clutch. The clutch goes all the way down to the floor with zero resistance. Clutch is not disengaging as it can be started in low range 1st gear and driven ok.


I replaced the Master cylinder about 3 months ago and the slave appears to be ok and has no leaks. I have removed the slave cylinder and the push rod in the bellhousing is easily pushed back and forward by hand - I assume that this is not normal?????


I am happy to pull the gearbox out completely and have a look as I need to replace a heap of leaking seals. just want to make sure that I haven't missed anything obvious


Thanks in advance, this aulro.com is a huge help

Hi mate

The clutch release fork inside the bell housing is esentially a lever which has a hemispherical depression/indentation in it which forms a pivot point over a post with a rounded polished ball at the top which sits in the indentation. When you push down on the clutch pedal it causes a piston to press against one end of the lever which then causes the lever to pivot and force the cutch plate off the flywheel.

Over time the surface of the depression in the clutch release fork starts to wear thin. Really this lever should be replaced at every clutch change in my opinion. (I seem to remember that some of them may even have a plastic insert to reduce friction but this just weakens the thing). One way or the other, there is a load of force involved at that point and eventually the metal wears so thin that the rounded ball punches straight through the lever, particularly if you have an old one which has never been replaced or an aftermarket cheap replacement.

At that point you have no lever and you get exactly the symptoms you describe with the piston al the way out inside the belhousing and pushing against nothing. Because there is no spring to force it back in, (i.e. the clutch spring), it feels as though your clutch is all the way down and there is no resistance whatsoever other than the lightweight return spring on the clutch pedal. Typically you will have felt a bang as it let go, and then absolutely nothing.

Take the inspection plate off the bell housing and look inside with a torch. On the left hand side about half way up you will probaby see a post which has conspicuously punched straight through the clutch release fork.

Cheers

Alistair

Originally Posted by Alistair

Hi mate

The clutch release fork inside the bell housing is esentially a lever which has a hemispherical depression/indentation in it which forms a pivot point over a post with a rounded polished ball at the top which sits in the indentation. When you push down on the clutch pedal it causes a piston to press against one end of the lever which then causes the lever to pivot and force the cutch plate off the flywheel.

Over time the surface of the depression in the clutch release fork starts to wear thin. Really this lever should be replaced at every clutch change in my opinion. (I seem to remember that some of them may even have a plastic insert to reduce friction but this just weakens the thing). One way or the other, there is a load of force involved at that point and eventually the metal wears so thin that the rounded ball punches straight through the lever, particularly if you have an old one which has never been replaced or an aftermarket cheap replacement.

At that point you have no lever and you get exactly the symptoms you describe with the piston al the way out inside the belhousing and pushing against nothing. Because there is no spring to force it back in, (i.e. the clutch spring), it feels as though your clutch is all the way down and there is no resistance whatsoever other than the lightweight return spring on the clutch pedal. Typically you will have felt a bang as it let go, and then absolutely nothing.

Take the inspection plate off the bell housing and look inside with a torch. On the left hand side about half way up you will probaby see a post which has conspicuously punched straight through the clutch release fork.

Cheers

Alistair

While commonplace with later gearboxes, unless I am mistaken, the release lever in Series 3 is forged not pressed, and this scenario is very unlikely.

John

Hi guys I have had more of a look today I think the movement on the slave push rod is normal after looking at some youtube videos. Leaning more towards hydraulics now.

I can bleed the slave ok but as soon as I tighten the bleed screw the master cylinder does not seem to push the fluid through and the level rises significantly when the clutch is depressed. This also happens when I clamp the flexi line. Zero resistance from the clutch pedal.
Is my new master cylinder faulty??