Juddering

[robbiesmith]

Hello experts, may I pick your brains again?

In reverse, moving at snail's pace, all is well but moving a bit faster causes a very noticeable judder.

Any ideas?

Clutch? Suspension?

All is well in first gear (and the other three) only in reverse does the judder appear.

Your help would be greatly appreciated.

[aupickup]

GEARBOX STEADY CABLE

[bmcecosse]

Engine steady/cable as above^^/engine mounts gone soft - but most likely - oil on the clutch plate.

[Old Nick]

hi,on the subject of steady cables,i have a 1098 with ribbed gearbox,and dont seem to have a "steady cable" on the gearbox,I have what looks like an earth cable (braided like one on battery) connected from box to cross member,is it missing (the Steady Cable that is) or were some model's without ? I too have juddering in reverse !

[MarkyB]

I won't change juddering, it was fitted to stop the engine moving forward under very heavy braking and the fan chewing up the rad.

I've tried replacing the engine and gearbox mounts as well as the engine steady rubber to cure reverse juddering.
Didn't work.

I'm still in denial about it being the clutch, how long are you in reverse anyway?

[les]

We've been here before and although establishing that the cable stops the engine moving forward, it does also have the ability, if too slack, to cause juddering.

[mike.perry]

My Series MM judders uphill in reverse, especially noticeable with the trailer on. It has no engine steady bar and has a new clutch. It is probably play in the diff in my case. Just give it a few more revs and slip the clutch.

[bmcecosse]

It's because it has no steady bar!

[MarkyB]

How slack is too slack then?
I adjust so there is no pull and the minimum of slack.

"We've been here before", before my time i guess, I'd be interested to know the reasoning.

[robbiesmith]

Thanks everyone.

I'm going to try accelerating hard in first gear to try to clear any oil from the clutch plate, as I have been advised to try elsewhere.

[robbiesmith]

Just drove up to Motorline in Firle where we were able to take a good look underneath. A small hole in the o/s front chassis member to be cut-out and welded, otherwise all is very sound under there; Phew.

However the bell-housing was being held on by only two bolts, top-left and bottom-right. There are now a full set of bolts holding it in place but this is unlikely to have been the cause of the judder. Andy Melville echoes the opinion that the cause is likely to be an oily clutch.

I'm not too impressed by the 'Classic Car Expert' who was said to have had the maintenance of this car for the previous owner. Apart from this, one of the first things I had to do was to calm the tick-over down, as it was running at nearly twice the normal speed, and I discovered that the fuel-gauge sender had been fitted without a gasket when I went to replace it. This was causing a slight but pervasive smell of petrol in the car.

I will not be naming names though . . . .

[MarkyB]

'Classic Car Expert'

Is a sales pitch really, when I got my car it had been serviced by the same trusted garage for years, I think the only thing they ever did was change the plugs occasionally as they are visible.
They had either used second hand oil or just never changed it .

If you want to try and burn the oil off the clutch you need to slip it very aggressively, in 2nd or 3rd rev the engine and hold the clutch just on the bite point until things get smelly.
Unless it's slipping it doesn't matter how fast you accelerate.

I'm not recommending this by any means.
As I said before, how much time do you spend in reverse?
Factor in how long does it take to replace the clutch finds me putting up with a bit of juddering.

[robbiesmith]

Thanks Marky,

I had been thinking about this and was already leaning to the conclusion that reversing gently to avoid the judder was preferable to causing it too much stress to get rid of the oil.

Thanks for your wise words which have hardened that leaning into a decision.

[MarkyB]

<Blush> If it isn't really broken don't fix it.

I believe it's called cost/benefit analysis these days.

[robbiesmith]

Don't blush, Marky, common sense is an uncommon thing - it took me a while (and some help) to get there!

[chickenjohn]

Thanks everyone.

I'm going to try accelerating hard in first gear to try to clear any oil from the clutch plate, as I have been advised to try elsewhere.

That is not bad advice, or slip the clutch and rev it in 4th as you are cruising along. Seemed to help my traveller reduce it's judder for quite a while.

[bmcecosse]

Yes - but DO NOT use 1st gear - that's poor advice! You may break a half -shaft! If you really want to test the clutch - use 4th gear - rev up the engine and lift your foot straight off the clutch (obviously - empty road/carpark ahead!) - and see what happens. If it stalls the engine pretty much right away - it's fine' If it slips like mad - it's obviously not fine/contaminated in oil........The remedy being obvious.

[silloyd]

Just to share a personal experience...

When I first got my car I had juddering problems (worse in reverse than forward) and had the clutch replaced 'cos I came to the same conclusion as others on this thread. The new clutch greatly improved but didn't eliminate the problem, so I just lived with it.

Later on, as a consequence of another job, I had to remove the prop shaft. On inspection there was play in both of the UJ's, so I replaced them and now there is only the faintest amount of judder in reverse; none in first gear - I guess there is still a smidge of play somewhere in this 40 year old car (Diff?) but not worth looking for it.

[robbiesmith]

Thanks for that silloyd; I've been underneath, checked the UJs and pushed hard on the prop shaft. The only problem I found was five missing bolts from the bell-housing which have now been replaced.

I've decided, as you did, to reverse gently and avoid the problem.