Clutch Judder after replacement

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Dazbaby
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Re: Clutch Judder after replacement

Post by Dazbaby »

The garage did show me such a tool and maintained that they used it however I still have a judder problem and a Valeo technical guy suggested that it was a possibility the plate may have been fitted the wrong way round. My main question would be, would this lead to a judder in 1st and reverse only?
Cheers
Darren

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white exec
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Re: Clutch Judder after replacement

Post by white exec »

Is the action of 2nd, 3rd, 4th and 5th always smooth and free from judder at all engine revs, even low ones, or are you just tending to use higher engine revs in these gears?
What happens if you pull away from rest in 2nd?

I'm also wondering whether the engine/gearbox mountings (and any movement stablisers/cushions) have been put back correctly, after the 'box was removed.

1st and Rev do have to cope with a good bit of low rotational torque, and that asks quite a lot from engine mountings and everything being secure. At higher revs and gears, the power unit needs a lot less "tying down".

Just thinking aloud.

Dazbaby
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Re: Clutch Judder after replacement

Post by Dazbaby »

Hi Chris,
That’s a good call reference trying to pull away in second gear - I haven’t tried that yet and will do so tomorrow. I haven’t noticed any juddering in normal use in any of the other gears. Having manually, ie. by hand, tried to rock the engine to detect any engine mount issues there was nothing obvious but doing it the way you suggest will be worth a try.
Thanks
Darren

Dazbaby
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Re: Clutch Judder after replacement

Post by Dazbaby »

Hello,
Just tried pulling away in second gear and yes it still judders to an extent, albeit to a lessor extent than first or reverse gear - perhaps because you need a little more revs in second to pull away smoothly.
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Darren

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white exec
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Re: Clutch Judder after replacement

Post by white exec »

Another test, for clutch and engine mountings:

Parked, handbrake firmly on
Engage 1st, and slowly come off the clutch pedal until the clutch starts to bite
Try this at idle first, and afterwards at about 1500rpm steady throttle.
Hold the clutch there, or lift off just a little further, and judge whether the pull forward is constant, or in a series of lurches/tugs/judders corresponding to each engine rev.
Looking to see whether the clutch is running true, or friction is not steady.

Try the same in Reverse.

Going back to 1st, as the clutch comes up, look to see whether the engine moves about unduly, particularly up/down.
A bit of engine movement fwd/back against the stops is normal, but power unit should not waggle about.
_____________

As an aside, although the long springs in a dual mass flywheel are there to absorb engine rotational vibration, one of the downsides is that the springs in the flywheel will compress by a significant amount when pulling away, and by a very large amount when attempting a hill start. This can lead to what feels like poor clutch control, when pulling away seems a choice between not enough traction, or too much (which can even produce an unexpected engine stall). From the driver's standpoint, this poor clutch action can only be remedied by using higher than usual engine revs, in an attempt to smooth things out. Even new DMFs can behave like this, while it is unknown on a standard SMF in good condition.

A Valeo DMF kit should work well enough when new, though, if properly installed. I realise that is the $64,000 question, though.

Dazbaby
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Re: Clutch Judder after replacement

Post by Dazbaby »

Hi Chris,
Thanks very much for the input. Having tried second gear pull always a bit more I can say that the juddering is definitely much less than first or reverse. However in second without more than normal revs the engine is more likely to stall abruptly. I will give your suggestions a try tomorrow and report back and thanks again for the advice.
Regards
Darren