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New Clutch Shudder
https://www.ausmini.com/forums/viewtopic.php?f=2&t=52941		 Page 1 of 2
Author:  Drexxle [ Wed May 06, 2009 3:41 pm ]
Post subject:  New Clutch Shudder
Need some advice on what would cause clutch shudder. I did a clutch kit a few months ago, and had a very minor shudder. Then i broke the clutch arm.


Now the system, new master, new slave, new lines, liquid side perfect. After today, new casing, new plunger, new timken bearing, new arm, new pin. So all round new throughout.

Put it all back together, and clutch works great, no problems. Get it into gear take off up through third, then gear down and mega shudder.

This wasnt there before i removed the casing, and i didnt touch the flywheel.

Any ideas. Been through engine mounts, all the simple stuff.
Author:  drmini in aust [ Wed May 06, 2009 3:49 pm ]
Post subject: 
One cause of clutch shudder when downshifting is the drive straps not sitting parallel to the flywheel.
If they are sitting at an angle, they bend when you gear down (the straps are then in compression).
This problem happens when people face the flywheel and backplate because of wear, then throw it back together without checking to see the diaphragm spring is flat when all assembled.

I had to take .060" off the 3 ears on one backplate recently. After I did this the spring was flat, and drive straps were parallel again.

Another common cause of clutch shudder is aftermarket cheapo clutch plates. Some Far Eastern ones have the appearance and suitability of a cornflakes packet.
I like the black Borg & Beck > AP >`whatever it's called now' brand, they work good and last too.
Author:  Mini_Special [ Wed May 06, 2009 3:59 pm ]
Post subject: 
Dang it he beat me to it!

Yep that was my guess also
Author:  TheMiniMan [ Wed May 06, 2009 4:11 pm ]
Post subject: 
There is also an issue with "Centralisation" of the throw-out bearing & it`s carrier,,, the clutch cover change may have effected a slight miss-alignment of the throw-out bearing to the center of the crank

this was very prominant in later minis & the factory tried to cover the symptom up by producing the "self-centering" throw-out bearing carrier

The factory also had quite a number of warrantee claims over this problem & a whole heap of minis were taken back, & the cover was then centered using the factory cover centering tool, & the cover was then doweled to the primary case

soo,,, maybe you have shifted the center line of the throw-out bearing with the change in clutch cover

maybe a self-centering carrier is needed... or if you can sort a "Centering tool" then you can centralise the cover correctly & fit it all back up again nice & true to the crank centre line

a tiny bit off here & the tin hat assy wants to wobble when the throw-out bearing pushes slightly "off-set" against the tin hats thrust washer.

I don`t think i`ve ever typed sooo many "Center" words in one post ever before :-)

If you have understood all what i`ve just typed then you`re well on your way to fixing the problem,,, if you havn`t understood then please don`t ask me to explaing it again,,, just way too many centers to type :-)
Author:  drmini in aust [ Wed May 06, 2009 4:21 pm ]
Post subject: 
And you have said `center' instead of `centre', repeatedly Matt.
We speak the Queen's English here mate, not Barack Obama's... :lol:

But I note the TV stations can't spell `gaol' correctly either, so it's not just you. :wink:
Author:  gafmo [ Wed May 06, 2009 4:43 pm ]
Post subject: 
Can I correct him, can I, can I :roll:
Author:  Drexxle [ Wed May 06, 2009 4:46 pm ]
Post subject: 
hahaha

i think matt is nearer to what im experiencing, Ken showed me a self centering bearing. The new timken has a large and flatter face than the old bearing as well. Given that theres no play in the casing now around the plunger, would i be better to put the old casing back on with the new parts. It would mean the bearing seating offset at first, might wear the bearing out quicker. But the play in the casing could be what was taking the shock of the shudder before.

The older bearing was completely shot as well, would i be better replacing the diaphram on the clutch, the flywheel and ring wheel are standard and im pretty sure havent been machined.

Im short of pulling the flywheel off and double checking the whole lot back together again.
Author:  Morris 1100 [ Wed May 06, 2009 5:05 pm ]
Post subject: 
Oil leaking onto the clutch can cause a shudder.
Author:  850man [ Wed May 06, 2009 7:39 pm ]
Post subject: 
Broken crankshaft can cause clutch shudder :lol:
Author:  74snail [ Wed May 06, 2009 7:39 pm ]
Post subject: 
Oil leaking ! Which is what I think I,ve got, its worse in reverse. I,ve never replaced that timing case oil seal before apparently its an engine out job. So you either let the clutch destroy its self or you take the car off the road and do it properly, since the car will be getting a new head,manifold,carby,extractors and exhaust I,ll do the seal at the same time.
Author:  drmini in aust [ Wed May 06, 2009 7:56 pm ]
Post subject: 
74snail wrote:
Oil leaking ! Which is what I think I,ve got, its worse in reverse. I,ve never replaced that timing case oil seal before apparently its an engine out job. So you either let the clutch destroy its self or you take the car off the road and do it properly, since the car will be getting a new head,manifold,carby,extractors and exhaust I,ll do the seal at the same time.

It's quite easy to do the timing cover seal in the car. And it's not too hard to do the clutch seal in the car, either.
Just don't try and do both in the car at the same time.. :lol:
Author:  John Smidt [ Wed May 06, 2009 8:20 pm ]
Post subject: 
I do not think the bearing Mat is talking about is the flat faced bearing
Author:  TheMiniMan [ Wed May 06, 2009 9:00 pm ]
Post subject: 
I`m talking about the bearing "Carrier"... the "Carrier",,, not the bearing

The later """"Carriers":""are "self-centering" type & the bearing is held onto it by a speed clip

You can fit either type bearing 3w5/8 or the crappy replacment 7w5/8 on the late type self centering carrier

I`m far better at maths than spelliengg :-)
Author:  sgc [ Wed May 06, 2009 9:16 pm ]
Post subject: 
TheMiniMan wrote:
I`m far better at maths than spelliengg :-)


Nooo, never... :shock:
Author:  Drexxle [ Wed May 06, 2009 9:50 pm ]
Post subject: 
Oil leakage causes slipping, which is not the same as shudder.

I went for a good drive this afternoon, and its shuddering slightly changing up the gears, but only slightly. When coming down through the gears, into 3rd is SHUDDER, 2nd, SHUDDER, really really bad.

Im tempted to try the old housing. Maybe the play around the plunger is allowing the bearing to meet flush. I can see what Matt means by the bearing hitting slightly offcentre.

Im also going to check the driving straps. Im gathering these are put on in pairs, each of the three sets made up of two straps so six altogether.

Such a shame cause i actually have a good clutch for a change.
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