43 replies to this topic

[davejf]

yup, I've used a new plunger and the press release bearing, and at low revs i get some real judder, i think its more obvious in my moke due to the open nature of it.

Guess i'm just going to have to get used to it then. Just seems wrong as it shakes the car, can't be doing it much good!

[MRA]

Ok,

If the engine mounts are good, all new parts are fitted, no oil on the clutch, narrows it down a little.....

Was the plate the solid type ? did it have the 6 springs (although not normally fitted to a bonded plate) ?

What cams are you guys running ??

Balancing will not make the slightest difference to this issue....

Breaking clutch arms..... will also not make any difference and also would have been a secondary issue failure, ie the ball fell off because of wear not because of weakness in the material, unless you were unlucky to get a new one with a fault.

The uprated arm and plunger is only to raise the durability due to lower wear rates, and will have an effect on your judder.

Did you clean the grease/oil that was on the flywheel / backplate before fitting ?

Edited by mra-minis.co.uk, 13 December 2010 - 11:52 PM.

[liirge]

All parts new, standard cam in my instance and no primary seal oil leak!
Flywheel had a huge dose of brake cleaner applied to it, as did the back plate and most over clutch parts - made sure 100% clean!

Edited by liirge, 14 December 2010 - 12:29 AM.

[liirge]

not 6 springs either

[davejf]

Ok,

If the engine mounts are good, all new parts are fitted, no oil on the clutch, narrows it down a little.....

Was the plate the solid type ? did it have the 6 springs (although not normally fitted to a bonded plate) ?

What cams are you guys running ??

Balancing will not make the slightest difference to this issue....

Breaking clutch arms..... will also not make any difference and also would have been a secondary issue failure, ie the ball fell off because of wear not because of weakness in the material, unless you were unlucky to get a new one with a fault.

The uprated arm and plunger is only to raise the durability due to lower wear rates, and will have an effect on your judder.

Did you clean the grease/oil that was on the flywheel / backplate before fitting ?

Hi Martin,
yes the plate is solid with no springs.
i'm running a 286 cam
all the clutch was clean when it went together.

Cheers.
Dave

[davejf]

Hi Guys,
Right, after putting some miles on it has got slightly better but nowhere near a level i'm happy with as I can't accept that that much judder won't do any damage and i'm not prepared to risk my engine.
I've now taken it apart again to have a look and see if I can figure out what the problem is.
I've taken the attached photos so am after some comments please.
I'm not happy with the crud on the primary gear splines, but the old verto clutch was on this before without problems, could this be the issue?
Also, the clutch plate is a little patchy, is this the problem and if so will it wear in with more miles (only done 100ish so far) or is there something wrong with it?
On the plus side the flywheel and pressure plate seem to have wear evenly all round so no high spots or anything.
So, over to you guys, where have i gone wrong?

Cheers,
Dave.

Attached Files

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[minidaves]

that back plate dont look in fantastic condition to me

dave

[MRA]

Flywheel looks good, no high spots.... ie inconsistent markings on the friction face.... The plate looks like it could benefit from more bedding in, however I would "rough" up both friction surfaces of the flywheel and backplate to allow them to bed in quicker

[davejf]

that back plate dont look in fantastic condition to me

dave

It looks better in real life. It was brand new when it went in.


Martin,
That was one thing my Dad has suggested too, so i think that may be the next move.



Maybe it will get better with use.

Cheers Guys.

[MRA]

somtimes the surface can be too smooth, or worse different surface finish from side to side....... or different materials, but the materials one is a long shot with your judder

[davejf]

somtimes the surface can be too smooth, or worse different surface finish from side to side....... or different materials, but the materials one is a long shot with your judder

The flywheel and pressure plate feel very similar if you run your finger across them but they are very, very smooth.
I'll try some fine emery cloth on them tomorrow and put it all back together and see what happens.

Thanks for the help.

Dave

[Cooperman]

Clean the entire assembly with brake&clutch cleaner.
Lightly rub the friction faces of the centre plae with 240 grit abrasive cloth/paper.
Re-assemble.
If it still judders, bed the clutch in by putting the car in 2nd gear, adding some revs, say 2500 whilst having your foot firmly on the brake. Slip the clutch whilst keeping the revs up until the clutch gets quite warm. That should cure it. You may have to repeat this a couplke of times.
If it doesn't, it may be that the centre plate is too hard a material for the application. You have a 286 cam, so have you lowered the final drive ratio, as 1st could now be too high for the clutch plate selected.

[davejf]

Clean the entire assembly with brake&clutch cleaner.
Lightly rub the friction faces of the centre plae with 240 grit abrasive cloth/paper.
Re-assemble.
If it still judders, bed the clutch in by putting the car in 2nd gear, adding some revs, say 2500 whilst having your foot firmly on the brake. Slip the clutch whilst keeping the revs up until the clutch gets quite warm. That should cure it. You may have to repeat this a couplke of times.
If it doesn't, it may be that the centre plate is too hard a material for the application. You have a 286 cam, so have you lowered the final drive ratio, as 1st could now be too high for the clutch plate selected.

Thanks Cooperman,
I'll try all that tomorrow. The final drive is 3.44, but it does have a close ratio box.

The part number from minispares for the plate is C-AHT596

Edited by davejf, 17 December 2010 - 07:08 PM.

[Cooperman]

I did once have an 'S' with a 544 cam, which is very similar to a 286, and a 3.44 diff with a SC CR box. First gear was far too long and the clutch took lots of hammer and did tend to judder a bit as it was a rally pressure and centre plate (grey diaphragm, I think). I had to fit a 3.9:1 FD to make it all work, which is what I use in my current rally 'S' with a 286 cam, comp clutch, lightweight steel flywheel, etc.
If there is any tendancy for the clutch to judder, it will with that 'long' first gear needing lots of clutch slip. Wait until you try to pull away up a steep hill!!!

[Cooperman]

I once had an 'S' with a 544 cam (very similar to the 286), a 3.44 diff and a SC CR box. First was really too high and I ended up fitting a 3.9:1 which was then excellent. As I recall I had a lot of judder with the 3.44 fitted, but when I fitted the 3.9:1, plus a new clutch plate, it was perfect although I can't say whether the judder was due to a faulty centre plate or the high 1st gear.
My current 'S' historic rally car has the 286 with a light steel flywheel, SC CR box, 3.9:1 FD and a comp clutch assembly and although heavy, the clutch is very smooth.
With a 3.44:1, wait until you try to pull away up a steep hill - blooming nightmare of clutch slipping!!

Edited by Cooperman, 17 December 2010 - 07:13 PM.