V8 Clutch Plate - how thick is it.

you can't really go by the thickness, but do have a look at the depth to the rivet heads, if much less than a couple of mm I would say replace it, unless you find a clutch change an easy job (and I mean that literally, as I would not mind a clutch change on an average rear wheel drive vehicle, whereas I would avoid it on a fwd)

mrcheerful

I would go further - change it unless you have good reason not to (not keeping the car long, likely to be used for very low mileage, have another engine out job planned in the not too distant future etc.) Otherwise, when the clutch does eventually need changing, it is likely to be when you can least afford to spare the time or money!

Depends on the car. Changing the clutch on the FWD Triumph 1500 is a doddle - but then that engine is fore and aft and not transverse!

Jim

Is this an unknown clutch? Have you driven the vehicle it came out of?

Its easy to do with the box out now, but a lot more difficult to do once the engine/box is back together and in the car, so you save yourself future hassle anyway.

If you have no knowledge of the clutch, even if the clutch has plenty of lining, you've got no gauarantee that the pressure plate isn't warped....

Alex

I drove the SD1 it came from for a few weeks, it seemed OK. There was an occasional but marked very short dip in power under hard acceleration once or twice, I put it down to fuel feed at the time (old carbs and pump) but I supopse it might been the clutch slipping ? There was a fair bit of travel on the pedal before biting point, but nothing that caused me any concern - it was still a good way off the floor.

But ideally the biting point is further away from you, not nearer !! The biting point usually gets higher with wear, not lower, this is because the springy bit has to press a bit further on the thinner plate.

mrcheerful

Not necessarily. If you have a hydraulic clutch then the bite point stays in exactly the same place, right at the top of the pedal travel, regardless of how worn the clutch is.

Drive a landrover, you'll see what i mean.

Alex

I have a landrover. It's clutch seizes to the plate if left for more than a month or two. I agree that hydraulic usually stays about the same, but it should still get a little higher when it gets really worn, after all, with a completely worn out clutch you can bring your foot right to the top and it still won't move !

mrcheerful

Next time try taking off in top gear - it will either stall or you should feel the clutch slip.

"mrcheerful ." realised it was Thu, 22 Dec 2005 07:19:30 GMT and decided it was time to write:

The clutch in my Spitfire used to do that every winter, while laid up in a single wall unheated garage. I cured it - and some other issues - by building an insulated & heated garage for it.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Jim Warren" saying something like:

The Datsun Cherry clutch was a 20min job - utter simplicity. I suppose more powerful engines don't use the method as it would involve a loss of bellhousing strength.

Wouldn't it have been cheaper to fit a new clutch every Spring?

Alex

Alex realised it was Fri, 23 Dec 2005

Fitting a new clutch would be completely unnecessary, as most seized clutches, including the one in my Spit, are easily unseized by various brute force methods.

I do admit building a new garage was a bit over the top. Then again, the new one houses four cars easily (as opposed to just one and a lot of rubbish in the old one), so it was worth it.

A broom handle or similar to hold the clutch disengaged before you lay it up works well. Brute force disengagement methods work, but they're a pain and you can look like a wally and attract the neighbours' attention banging and wailing and screeching around trying to unstick the clutch in the spring. BTDT.

About 45 minutes, once you know what you are doing, to do a classic Saab

On a cable clutch you could jam it open, but I think a hydraulic would probably just leak its fluid away, then you have two problems ! Other vehicles don't stick, I don't really understand why the land rover does.

mrcheerful

Dean Dark realised it was Thu, 22 Dec 2005

It probably wouldn't work with my Spitfire, as the clutch hydraulics leak ever so slightly. Enough to engage it after a week or so.

Fair enough. I've only ever used that trick on cable clutches.

The engine and box are right out of the car, the box was removed so I could get the lump up on the stand and it was then just a two miinute job to get the clutch off and plate off.

It was just whether it was worth putting a new one in - I will, having read the posts - should I renew the cover while I am on?

if money is no object, then yes, personally, on a toy project I would inspect and decide, rather than change willy nilly (same for the clutch plate and the thrust bearing. and the spigot bearing)

mrcheerful