5 replies to this topic

[m1n1]

I have a 23 year old 1380 with pre verto clutch that runs quite well, but is suffering with cluch judder on pulling away.  I did some clutch maintenance after watching some videos online, machined down my black plate horns so the spring is flat when everything is tight, centralised the backplate with a dti before tightening everything.  Went up to 9 straps and upgraded bolts, Nos Primary gear and shimmed correctly. New flywheel housing.  Made sure everything was clean before reassembly but it still judders.    

I noticed the release bearing witness marks are ever so slightly off centre on the diaphragm removable centre boss, thought that could be the problem but then the boss has a small amount of movement when in position without the locking spring - so maybe it wasnt perfectly central (can be adjusted) but not sure.

 

Any ideas? perhaps a new clutch plate will sort it.   When the engine is cold its alright, but when warm its not - and only on pull away, if i rev over 2000rpm its fine but in heavy traffic its not always possible to do that and i hate to think what the juddering is doing to the primary gear bushes and drivetrain.  

 

its a mish mash of parts i've bought throughout the years

 

minispares lightweight pre verto flywheel 2005

minispares lightened backplate pos the en8 one 2007

med clutch arm and plunger 2010

normal solid clutch plate 2010

Orange diaphragm 2007

 

i've never balanced anything either its always felt good :)

[sonscar]

How are the engine mounts and steady bars?Subframe mounts?unlikely but often overlooked as judder causes.Steve..

[nicklouse]

What has bells ringing to me is the having to use a DTI to center the back plate. The design of it puts it in one position that has to be correct. If it was not you have issues somewhere. I would also have it balanced but that will have no bearing on judder.

 

again not knowing how things were done I have to ask are the two friction surfaces parallel?

 

and finally the friction plate may be at fault.

[Spider]

Some of the causes of Clutch Shudder are;-

 

Oil on the Clutch,

Incorrect Bolts on Drive Straps fitted (must be shouldered bolts),

No washer between the Drive Strap and Flywheel,

Worn Primary Gear Bushes (this will sometimes show up as oil dripping from the split pin breather at the bottom of the housing but not always),

Stretched or unequal length Flywheel Drive Straps,

Thrust Bearing on the way out or misaligned,

Soft Thrust Plate on Diaphragm

Loose Flywheel ,

Worn Clutch Plate - although usually you'd be noticing it slipping first,

Flywheel and / or Backing Plate in need of machining,

Bent and / or cracked Crankshaft

 

Noted that some of these you have already looked at.

One thing that grabbed my eye from your post was the witness marks from the thrust bearing on the thrust plate. noted the plate has some play, though, it will likely loose that ones some pressure is put on the plate. The Clutch Cover while spigotted in to the clutch housing, does have a fair bit of clearance, seldom do they go back on exactly from where they were taken off, this in turn misaligns the thrust bearing, which as it drags across the thrust face, will often judder. With the original 3W5/8 bearings, this was seldom an issue as they had a nice wide hard face which would slide on the thrust plate, as both a very hard.

 

The later 7W5/8 bearings, however, did (do) give grief as their face is quite narrow and so has a tendency to grip on the thrust plate rather than slide. For a while, the factory overcame this by aligning the clutch cover bang on centre and fitting 2 roll pins for precision location of the cover. There was a tool available for doing this alignment, I do have one, but I have no file photo of it.

 

Later again they went to a floating thrust baring, that was held in place with a speed clip, these would self align when the clutch was used. I'm not sure if thise type of plunger is still available these days.

One other item that grabbed my attention was the orange diaphragm. Having the higher spring pressure here can also lead to judder. If you haven't yet tried one, fit a standard blue dot diaphragm.
 

 

 

[Lplus]

I see various changes to part specifications at different times.  Did this problem start after any of those changes, or is this something new?

[ACDodd]

I find when using a steel flywheel to use an iron backplate with it, this reduces or removes judder.

Ac