Juddering under braking (not warped disk) driving me crazy
 

I have had a juddering under braking for a while now. When braking hard there is no judder. But braking steadily down from about 50mph or under there is a terrible shaking through the steering wheel.

At first I thought it was warped or deposits on my discs so replaced them. The problem was a bit better but never completely went away. I knew my shockers were on there way out and had a bit of play in them so replaced them. No improvement. The 4 pot calipers were also reconditioned not long ago.

Thinking now of maybe replacing both hubs to see if that sorts it. What do you think?

It's driving me to the point where I'm thinking of selling the car to get rid of the problem.

Please has anybody got any ideas what can be causing this?

If it's nackered hubs, the discs will move with the hubs and push the pads back. Your foot will go to the floor when you press the pedal! Have you looked at the bushes in the bottom arms? If they have movement it can create the same feeling.

Will have a look tomorrow thanks. Anymore ideas as to what it can be??

as said check your bottom arms for play, all the bushes, drop links, wheel bearings, wheel balancing? are you calipers mounted central and true.

more than likely your new disc's are warped :(

Why would my new discs be warped ?
Or could something faulty be warping them?

Checked bottom arms out and no play, all bushes seem ok and doesn't appear to be any play in the wheel bearings. Running out of ideas :(

Did you get someone to press the brakes when you checked for bearing play using the wheel as leverage? This can help when checking bearings.

A check to see if the new discs are warped (and seated correctly) would't do any harm.

Track rod end.

I recall having steering wheel vibration under braking. Had the wheels re-balanced - cured! I'm assuming it was the dynamic balance (inner weights)

JohnD

Yeh you might want to check your wheels arn't bent (especially on the inner rim which is hard to see). Balancing can help alleviate small indents on rims but when you load them up by braking hard you can tell its not quite right. If they are bent a re-balance may help, but you might need new rims.

Let us know when you do find out what the culprit was.

Had the same issue on my newage, put new discs on as I though they were warped. Same problem. Turned out to be the wheel bearings, which in turn warped my new discs.

There was no whining noise though so bearings weren't my first thought.

hi did you replace the discs ? if not are you sure the fitter cleaned off the drive flanges properly before the new discs were fitted,??
how about the lower arm rear bushes did you check with a prybar or just visually??
if worn they will tend to move side to side under load,is your front tyres worn unevenly inner edges ??
only other option is for someone to check run out with a dti gauge as you cant use a rolling road with awd
oh on thinking about it do you know any local mot stations that instead of a roller tester use a digital brake plate tester that will print a graph showing spikes.might be worth a few phone calls?? good luck

I had a set of Tarox discs on a Mondeo which developed a vibration under braking. When tested, they had no run-out. I replaced them with a set of Bremsport which were perfect!
Consider this - when tested, the disc is cold. When you brake, the disc is hot. Doesn't take a rocket scientist to work out what's going on here?

JohnD

Thanks for all the advice, I've had a busy last few days + the weather hasn't been the best for getting under the car. Will try a few more things out and let you know if I get it sorted.