Help - Harsh judder at speed

[pdavison]

Hi Guys,

I need your ideas, this morning I was on the motorway travelling at the speed limit and all of a sudden there was a harsh juddering which was going right through the whole car.

I slowed down and pulled onto the hard shoulder and as I slowed the gap between judders lengthened. I initially thought it was a puncture but I checked the tyres and they are fine as far as I can tell.

I then pulled away again and everything was fine until two minutes later when the same thing happened again. I stopped checked everything and all appeared to be well so I started on my way again. Then sure enough two minutes down the road it happened again.

Finally when I pulled off the motorway and drove the rest of my journey into work, the car behaved absolutely fine.

So after all that rambling, has anyone got any ideas what might be up?

>>> Edited by pdavison on Wednesday 7th April 08:47

>>> Edited by pdavison on Wednesday 7th April 08:48

[olly]

How frequent is the juddering (once per wheel revolution?), and does it stop below a certain speed ?

[washy]

Does the handbrake release completly? I had a very similiar problem and found that the handbrake was binding slightly.

Washy

[pdavison]

It felt like once per wheel revolution, but it doesn't appear to happen until you go over 70mph and then once you do it happens below that speed until you stop the car and start again.

I'll check the handbrake too.

[dannylt]

Knocking rear brake pads - or does the sound not go away when you touch the brakes?

[kojak69]

What about UV joints on the transmission.

[satman]

kojak69 said:

What about UV joints on the transmission.

Beat me to it....although i assumed this was the problem with mine...checked all UJ's including propshaft...Juddering/vibration crept in at around 80/90 mph...main dealer had rear wheels balanced...In the end i took mine to a tyre place who balanced all 4 wheels using a state of the art digital balancing machine....(looked the dogs danglies this machine)...and cured it. I think you should also check for 'carbunkels'(Sp) on the inside walls of your tyres....

[arcbeer]

Sounds like you've thrown a weight off one of the wheels. This happened to me and was only noticeable at certain speeds.

[kojak69]

I cant see it being a weight thrown off a wheel due to it starting at speed, but then remaining until the car has stopped. Then again, i'm no expert. Very Puzzling.

[trooper1212]

satman said:

Juddering/vibration crept in at around 80/90 mph...

I've got this at the moment, but I'm getting 4 new tyres fitted on friday, so it's probably worth doing a full geometry check at the same time.

[pdavison]

I'm going to test it all on the way home.

I'll check the weights, maybe I knocked one off when cleaning the car as I do tend to try to clean the inside of the wheel as well as the outside !

It doesn't happen at idle so it could well be.

[kojak69]

pdavison said:

I'm going to test it all on the way home. I'll check the weights, maybe I knocked one off when cleaning the car as I do tend to try to clean the inside of the wheel as well as the outside ! It doesn't happen at idle so it could well be.

A weight off the wheel WON'T cause major judder at low/crawl speed. The centrifugel force is not great enough to cause it. An 'out of balance' wheel will cause judder at speed. I think your problem is elsewhere.

Still think its something to do with the transmission i.e. propshaft, UV joints etc.

>> Edited by kojak69 on Wednesday 7th April 17:35

[anonymous-user]

Could be Rear Differential Bush thats shorn?
(i.e Diff knocking about)

[flashheart]

Chap, I had the very same problem on my Sierra of all things. Took it into the local garage who instantly thought wheels. Turned out one rear tyre had 'lost' a huge chunck, about the size of outstretched hand, and was down to the cords. Very worrying to say the least! Did not see it because it was on the inside of the tyre and since you cannot really see ANY of a Cerbera tyre I suggest you whip the wheel off just to discount something that could really spoil your day.

[pdavison]

I have checked all the wheels and wheel weights and everything appears to be fine.

Drove home yesterday with someone following and kept below 80mph and experienced no problems at all.

So this morning on my way into work I stopped via a private test track (!) and tested the car all the way up to 100mph and there was absolutely nothing wrong, no shakes or juddering of any kind.

I'm going to get it checked out anyway, but I can only think that maybe something was stuck between the tread of one of the tyres or something similar. Since it happening last I've done another 50 miles and all is well so if I do discover anything I'll let you guys know.

Thanks for the pointers chaps.

[satman]

Could it be a UJ seizing up as it gets hot?...a long shot i know..but did you do any extra distance when it happened the other day?

[pdavison]

It happened after just 15 miles yesterday so I wouldn't think it would have been hot enough.

How can I check the UJ?

[kevin63]

Hi Paul
I have had this problem before and it was a easy one to cure, it was the hand brake on one side which was taken up too much and when you drive at speed it warms up and expands and starts to over heat which then causes the judder you got.
Just check both sides with car jacked up,out of gear and hand brake off and put the hand brake on click by click to see which side binds first, then back it off one or two clicks.

[pdavison]

kevin63 said:

Hi Paul I have had this problem before and it was a easy one to cure, it was the hand brake on one side which was taken up too much and when you drive at speed it warms up and expands and starts to over heat which then causes the judder you got. Just check both sides with car jacked up,out of gear and hand brake off and put the hand brake on click by click to see which side binds first, then back it off one or two clicks.

I think this may have been the problem, it appears to be fine now but I will keep an eye on it.

Thanks for all the ideas.