Clutch Release Bearing Clearance

[John042]

Hi All, quick question, is the clutch release bearing supposed to be in perminent contact with the pressure plate under slave cylinder spring pressure? Therefore turning when the engines running. Thanks John042.

[anonymous-user]

Mine does but I can't see it is supposed to be ..

[John042]

Thanks Cliffords, you've given me a little more asssurance. I only noticed the lack of play when fitting a replacement slave cylinder, (Landrover One!!)Anyway I refitted the original one only to discover this also pushed the release bearing into contact with the clutch pressure plate. In fact even when disconnected there is very little lateral movement available for the clutch release arm. Reading some posts on another forum (TR6) raised similar queries, the conclusion being that the bearing was designed to rotate with the engine running. Thanks again for the reply. John042

[Simon says]

John042 said:

Thanks Cliffords, you've given me a little more asssurance. I only noticed the lack of play when fitting a replacement slave cylinder, (Landrover One!!)Anyway I refitted the original one only to discover this also pushed the release bearing into contact with the clutch pressure plate. In fact even when disconnected there is very little lateral movement available for the clutch release arm. Reading some posts on another forum (TR6) raised similar queries, the conclusion being that the bearing was designed to rotate with the engine running. Thanks again for the reply. John042

RWD Fords had the release bearing in constant contact with the cover plate too,remember though the bearing is under no load like this

[spend]

If it isn't in contact what would keep the pushrod and pivot from clattering around + more importantly punching holes (even moreso) when the clutch is engaged?

[spend]

What about the arm? I don't recall any dead stop on that before contact on the release bearing?

[Ribol]

Quinny said:

spend said:

What about the arm? I don't recall any dead stop on that before contact on the release bearing?

Precisely, the spring in the slave cylinder, is pushing the pushrod into the arm, so the arm is pushing quite hard against the bearing, hence the bearing being pushed up against the cover plate under load

........ and also must be able to allow for wear on the clutch assy.

[Simon says]

Ribol said:

Quinny said:

spend said:

What about the arm? I don't recall any dead stop on that before contact on the release bearing?

Precisely, the spring in the slave cylinder, is pushing the pushrod into the arm, so the arm is pushing quite hard against the bearing, hence the bearing being pushed up against the cover plate under load

........ and also must be able to allow for wear on the clutch assy.

Good point Ivan seeing as the fingers on the clutch cover/pressure plate move out towards the gearbox input shaft with clutch wear.

Edited by Simon says on Thursday 20th January 19:43

[John042]

Thanks all, can sleep at night now. It was just something I'd not seen before possible because of the large hole in the TVR's bell housing. Make sense when you think about it. Clutch wear being compensated by the slave cylinder spring. That release bearing must take a hammering, spinning at engine rpm all the time even if it's not under any load. 'Big Geoff' could have checked his weeks ago and put me out of my misery, if he had some more 'ground clearance' Cheers John042

[big geoff]

i might be fatter than you but im younger and able to reach the pedals.Back to the clutch t5 box if the clutch is worn the realese bearng gets pushed towards the gearbox then it becomes in contact with the first motin shaft seal housing which could result in clutch slip

[John042]

Thanks Quinny, you're right there's not much movement on the clutch arm anyway even when disconnected. The Landrover slave cylinder did seem to have a stronger spring though, hence re-fitting the original cylinder. Big Geoff has never seen the underside of his Chim! He reckons the ground's too 'high' to get underneath or he's too busy posing in it. John042

[Kitchski]

If you've got more than around 2mm pre-load on that slave cylinder, your clutch could well be on it's way out. When the friction plate gets thin enough, it causes the fingers on the pressure plate to spring out more than normal. There isn't enough free movement in the release bearing/push rod/slave to allow for too much, and eventually you find it's all permanently under pressure. What eventually gives way is the release arm....the pivot uses pushes through it. When you replace the broken arm (which you can do in situ on a T5 box, not sure about the LT77) you find the clutch slipping and disengaged slightly....this is because theres no room left for movement and the only sure is to change the clutch.

So in short, some pre-load is normal as others have said, otherwise the release bearing would be flapping around. But the release bearing is only designed to rotate at engine speed while freewheeling ie not under load, so is it spinning becuase it's picked up friction from the clutch (normal) or because theres some weight behind it? (not normal).
Remove the slave and try to gauge how much pre-load you have. Pull the release arm out and inspect the dish the pivot sits in if you really want some clues. That's my angle.

Did it happen to me? Yes!