Clutch problems

[900ss]

Having just changed my noisy (3rd gear) gearbox it seems I’ve gone from bad to worse. I originally thought the clutch was also on its way out as it was becoming harder n harder to engage a gear at standstill n it was esp bad at selecting reverse without unwanted grinding of gears (tho it never slipped as such) Anyway I fitted a brand new clutch at the same time as changing the box n now I cant select gears unless I turn the engine off.
Its recently had a slave cyl as the old one seemed to be weeping so I cant see that being at fault n the master cyl is also a resent addition.
Odd thing is, if I start the car in gear it seems that the clutch works AND bites where you might expect it.
Crawling underneath I can “just” spin the release bearing, so I assume it’s preload is correct? I can also see the clutch cover fingers move as the pedal is depressed but obv something isn’t right still.
How should the clutch pedal on these cars feel? Are they known to be heavy or should they be lite as a feather? The pedal on mine has always been as lite as a lite thing. Does that sound right? (tho not actually in a chimaera but chimaera eng/t5 box/master cyl/slave cyl parts used)
Just an idea, could it be that fluid is leaky back into the master cyl as its deffo not leaking into the car, hence losing clutch pressure?

I’m running out of ideas fast
Anyone?

[Cider Andy]

Yes, that could be happening. Presumably you've checked that the master cylinder is topped up? If not, that's exactly how it would behave.

The clutch on my car (a 450 with a T5 gearbox) is quite heavy - I don't know what it's like in comparison to other cars, but I've heard the clutch is heavier with the T5 gearbox than with the Rover gearbox.

[900ss]

Cider Andy said:

... you've checked that the master cylinder is topped up? .

Levels were fine, if not a little blackened from the odd standing start abuse. Now changed for dot5 in the hope to relieve heat?
Could it be that's the prob?

[blaineuk]

take it for a run, i did my wedge clutch recentely and mine was the same for a while, but started to work right after a few changes

[GreenV8S]

I wouldn't expect to see heat blackened fluid in the reservoir, that is more likely to be residue from a seal that is breaking down. The symptoms you've got suggest that the clutch isn't releasing fully. This is most likely a hydraulic problem, either an internal leak at the master or just air in the system.

[900ss]

Cheers for the advice. I tried running the car in 4th with the clutch depressed but things still didn’t improve so I tried rebleeding a few times n that didn’t work either.
I think ive eventually found my mishtake ....


http://img.photobucket.com/albums/070

http://img.photobucket.com/albums/070

With the bearing preload removed the clutch fingers on the new cover seem almost straight, yet the fingers on the ol unit protrude outwards by some amount. Still not 100 sure yet but as I didn’t use the supplied bearing with the new kit (another story) it looks like that bearing is longer then the org one. I can only think that would allow more throw to release the clutch.
Does that sound right or am I missing something?

[ngr]

Hi 900ss

When you bolt the clutch cover on to the flywheel and it clamps the clutch plate the fingers will flattern as your pic. Was the clutch cover and plate brand new?

[Mad Mitch]

Morning 900ss.... The cover looks wrong to me.I doubt that thee will be sufficient travel on the fingers before contacting flywheel to clear gears correctly.There really is something fundamentaly wrong with the parts. In my opinion only of course.

[900ss]

Cheers
The clutch is a new kit as sold by techniclutch
You are right, the fingers do compress/decompress as I noticed when I removed the lot again this morning.

http://img.photobucket.com/albums/070

Theory no 2 now is the above bearing is what’s amiss? The supplied bearing in the kit doesn’t actually fit the tvr box (to small dia to fit over the carrier) that’s why I had to use the old bearing. I can only guess they’ve supplied the wrong bearing or have their data wrong? Measuring the new bearing it seems to come up as 3mm longer from where the arm operates on. I’m not sure tho that would be enough to cure the prob?



>> Edited by 900ss on Sunday 9th April 11:59

[900ss]

Mad Mitch said:

... The cover looks wrong to me.I doubt that there will be sufficient travel on the fingers before contacting flywheel to clear gears correctly.

Only thing for it. I’m going to go bolt the ol clutch back up to see if things are that diffo

[Ribol]

Is it possible to put the clutch plate in the wrong way round?

[900ss]

Nope, it’s not possible to get the plate back to frt
Further investigation reveals the added bearing length wouldn’t make up for the diffo in the two clutches now anyway
After bolting the old clutch back up you can see the fingers are still proud by 4-5mm

http://img.photobucket.com/albums/070
http://img.photobucket.com/albums/070

Now look at the new clutch n you can see the fingers are now recessed by atleast the same amount.

http://img.photobucket.com/albums/070

Looks like the clutch kit is wrong after all.

[mbu10]

never knew you wore nail polish

[900ss]

Only on special occasions

[Ribol]

900ss said:

After bolting the old clutch back up you can see the fingers are still proud by 4-5mm.

It could well be the wrong kit but the fact the fingers are lower is not the only thing to consider here. Measuring how flat the fingers are is not necessarely the right way to check the cover. To compare two different covers you should do it off the flywheel face down measuring the drop. You also have a new plate with thicker linings and spacer spring and a non worn cover face with the new assembly that is going to lower the fingers anyway.
Forgetting this car in particular for a minute, if you take the same cover made by AP and Laycock for instance the shell casting depth can differ making it seem the fingers are at different levels anyway. You can also get raised diaphragm fingers with a flat faced bearing as opposed to flat diaphragm fingers and a domed bearing - two different ways of doing the same job.
Not saying you are wrong about anything just adding in some things you may not have considered.

[900ss]

Hi Ribol
I appreciate your advice
The kit has now been sent back (with mine) to the suppliers for them to investigate.
Off the car both covers certainly seemed the same with them both having the same drop measurement from the tip of the fingers. In fact I’m sure they also shared the same embossed Borg n Beck part number.

New cover

http://img.photobucket.com/albums/070

As you say the plate was thicker as it was new, but not by much as the old unit wasn’t that heavily warn.

http://img.photobucket.com/albums/070

http://img.photobucket.com/albums/070

http://img.photobucket.com/albums/070

http://img.photobucket.com/albums/070

The only obv diffo that I can see there is the centre spline area is countersunk on mine whereas it’s flat on the new plate. I found another used 4.0 clutch today and that also was the same as mine, so it cant be my clutch is wrong.

[terence]

My 2penny worth. Does the drive plate slide smoothly on the gearbox splines and is the spigot bearing in good condition and not burred. Both/either of these can cause a dragging clutch.

[Ribol]

900ss said:

The only obv diffo that I can see there is the centre spline area is countersunk on mine whereas it’s flat on the new plate. I found another used 4.0 clutch today and that also was the same as mine, so it cant be my clutch is wrong.

The countersunk boss should not make any difference as long as the larger diameter flat version does not foul the centre of the flywheel. There do not appear to be any marks on it so that would seem unlikely.
Is this cover a recon, I have never seen an AP cover painted red, unless it is a TVR thing?
You seem to have covered all the usual things, you may just have a cracked diaphragm, it does happen, admittedly not very often. It is visible by looking at the cover but as it has been returned it’s too late to look.
It will be interesting to see how this one turns out, hope you get it sorted soon.

[900ss]

terence said:

My 2penny worth. Does the drive plate slide smoothly on the gearbox splines and is the spigot bearing in good condition and not burred.

I looked for both of those but they both checked out ok.

Ribol said:

Is this cover a recon, I have never seen an AP cover painted red, unless it is a TVR thing?

Advertised as new, but I read into it as meaning "recon" as it was "modified for fast rd use"