Clutch judder after moterway drive, goes away with use

[GrahamFountain]

Anybody got any ideas what this is. I've had the problem for a while, but it's intermittent and I forget to ask.

Yesterday I went down to Salford in the Sprint to use it as a tank transporter - fish tank that is. Motorway nearly all the way, and no gear changes at all for about 60 miles of reasonably fast driving. Anyway, when I got to the south end of the M61, where everything stops, it had developed this terrible judder setting off from stopped. After a couple of dozen of those - lots of revs and let the clutch out very, very gently -, it passed, and the clutch went back to be really nice and easy to use.

Comming home, same length of drive on the motoway with no gear changes, but no problems with the clutch at the west end of the M55. Obviously, there wasn't the same stop go work at the Blackpool end - not this time of year -, but there's a couple of roundabouts and traffic lights to get through. So I would have noticed, and it's clearly not happening the same every time.

As it's an intermittent, it's hard to be precise about when it happens, but I think yesterday's example is classic - it's definitiely mostly after a long run with no gear changes, and it goes away with use, not after letting the car cool down or anything. I used to have this problem with a TR7 Sprint a while back, and never did find out what it was then.

I'm wondering if its oil contamination from a leak from the rear crank seal that builds up with sustained running and cleans itself with some use.

Graham

[mbellinger]

Graham

I had exactly this problem with a VW Polo some years ago. After having the gearbox out four times, changing every single clutch component (twice) and then trying another known (excellent) gearbox, all to no avail; I changed the flywheel in desperation.

End of problem.

I have no idea if this will help you, but it certainly ended months of frustration for me.

[GrahamFountain]

Did you change the rear oil seal in all that and, if so, with or before the flywheel?

Graham

[NickMorgan]

I can't help, I am afraid, but I would be interested to know the answer, as my Toledo occasionally has the same problem once it has warmed up. Perfect clutch when cold, but just occasionally it judders after a long trip.
Interestingly, my modern(ish) Honda has the opposite problem. A dreadful judder when setting off on a damp, cold morning, that disappears once it has warmed up!

[geeksteve]

My Morris Oxford did that. About a month or so later the friction plate exploded...

[mbellinger]

Graham

When we had the clutch off there was no sign at all of oil contamination on it or the flywheel surface. So we didn't change it.

When we removed the flywheel and changed it for another, we changed the rear oil seal for good measure as it was exposed. It did not appear to be leaking.

I believe that the phenomenon is caused by overheating of the flywheel leading to distortion. Interestingly, when we removed the flywheel the clutch facing side was immaculate and showed no signs of distress. The engine facing side did exhibit such signs once removed and inspected and also had some small cracks around the centre. These were invisible from the gearbox side.

HTH

[Galileo]

Granny and sucking eggs here, but a similar feel to clutch judder can happen with a soggy gearbox mount that softens as it gets warm...

[series111]

I had the same problem earlier in the year with a juddery clutch and found it was the needle roller bearings in the u/j's in the prop shaft had worn, just a thought

[GrahamFountain]

Thanks for the suggestions. I'm certain this, and what I had with the TR7 Sprint, is closely connected to the clutch. That's mostly because, by careful operation of clutch and throttle, I can control it quite abit, if not actually emininate it. Also it seems mostly caused by driving for a while without changing gear or using the clutch, and I can't see what that affects around or after the gearbox.

I think it's definaitely that the clutch is catching the flywheel as it goes round, then letting go. In which case the flywheel distortion sounds a posibility. That's if it's not contamination, and slippy/sticky bits aligning and unaligning - that was the first suggestion from Steve at S&S.

Anybody have an idea how much the flywheel would have to distort to give that effect, and is that reasonable given the dimentions and temperature differences?

Graham