Breaking Judder From High Speed- Could It Be The Suspension?

[brownridge]

My 2001 gs430 (107k, full service history) has had new front discs and pads about 10k miles ago. Now it has developed a judder braking from motorway speeds suddenly. My specialist Lexus dealer thinks that the discs (or one of them) is warped.

However, at the same time, there is a judder throughout the steering wheel between 60 and 80. I thought wheel balance at first and have had that done....it's made no difference.

I am thinking that the wishbones or links might have play in them and that the wheel is not being held securely and that it's not the wheel balance or discs.

Any expert opinion out there?

Thanks

Allan

[is200 Newbie]

Have you considered sticking or seized brake calipers?

[ChrisIS200SportTTE]

I'd second a look at the callipers for binding/seizing.

[dave1]

Did your Lexus dealer actually check the discs to see or just say they may be warped? Did you tell them about the judder?

It is always worth getting several opinions from garages to see if they agree.....just don't tell them it has been diagnosed or checked elsewhere otherwise they might not check so carefully as they will possibly have preconceived opinions based on what other garages have said.

Best of luck and hopefully it will not be an expensive fix. When the problem is rectified don't forget to update this post for the benefit of members.

[dave1]

Another thought.....how long since the car had MOT......both in terms of time and also mileage. Were there any relevant advisories?

[mr2lad]

I had similar on my ls400 , changed brakes serviced calipers even changed alloys n tyres, new suspension and still a wobble on steering wheel and felt it thru seat as well...... End result was centre bearing on drive shaft....

[steve2006]

Any decent garage should be able to check the run out of the brake discs using a dial gauge either confirming the suspicion or eliminating them as the cause.

I had front brake judder on my LS a while ago (still fitted with its original discs) but before I had the chance to investigate I replaced a worn UCA as the ball joint was shot. This also eliminated the brake judder so there are lots of causes not just the discs.

[brownridge]

Have you considered sticking or seized brake calipers?

good call, in fact they found a sticking brake caliper. They freed it off and put copper seal on it and thought it was cured- handed it back to me. No it's not, so they are getting it back next week to check if the brakes are warped ( that's just their guess so far)

[dave1]

Their guess? While they freed caliper they could have checked disc. I asked re MOT because if it was fairly recent then any problem with links/wishbones should have been noticed even if they were only as advisory.

[brownridge]

Another thought.....how long since the car had MOT......both in terms of time and also mileage. Were there any relevant advisories?

Mot was done August 1st and was totally clean. Vehicle has done 12k since then

[brownridge]

After checking the discs, they were warped.... So new discs and pads. The car comes back tomorrow so hopefully that's it cured!

[ChrisIS200SportTTE]

But why were the discs warped is what you should be asking. Generally discs don't just warp. Common causes are not bedding in new pads properly, over tightened wheel nuts, brake pad deposits sitting on the disc causing 'bumps' and sitting at the lights with hot brakes and your foot on the brake pedal causing heat spots. Heat being the main factor to warped discs.

The only reason I mention anything is I had problems with warped discs on my Honda a few years ago.

I had judder just like you. Garage diagnosed it as warped discs so had new discs put on. 3000 miles later the judder returned. I had two slightly sticky front callipers that didn't stick on enough to give me any other symptoms until they had caused heat spots causing the discs to warp or something like that anyway.

What I do remember is being told by more than 1 garage that brake discs shouldn't just warp and if you have warped discs you need to find out why they warped or it'll just happen to your new discs.

[brownridge]

So they have said that the seized caliper has caused the warping.

[woodyk]

I bought a 2005 GS 300 with 45,000 on the clock - and it had an outrageous wobble on it when ever I went over 60mph and then a judder on breaking. I thought it would be a quick a fix on the wheels but then I started to investigate and found it could be a number of issues and that this is the infamous GS shake!!! needless to say after spending 6 grand I was completely bricking it!!

Anyhow the balancing is the first step and cheapest - so took it to the tyre shop in Chingford (which although are not the cheapest are worth the money, IMO) which revealed some donut had put a directional tyre on the wrong way and that the balancing was out. With this fixed I took to the motorway and shake had completely fixed itself - going up to 140 without any issue. However the breaking judder is still there..... :-(

Saw an American post and this guy stripped the wheel down to the hub and scrubbed it with wire wool till it was brand spanking new. At the same time he removed the screws which combine with the wheel nuts hold the entire assembly including tire in place (and scrubbed these too) - he claimed it fixed the problem but was wondering if anyone else has tried this? It seems like a lot of elbow grease for little reward!!! any thoughts welcome...

[dave1]

I bought a 2005 GS 300 with 45,000 on the clock - and it had an outrageous wobble on it when ever I went over 60mph and then a judder on breaking. I thought it would be a quick a fix on the wheels but then I started to investigate and found it could be a number of issues and that this is the infamous GS shake!!! needless to say after spending 6 grand I was completely bricking it!!

Anyhow the balancing is the first step and cheapest - so took it to the tyre shop in Chingford (which although are not the cheapest are worth the money, IMO) which revealed some donut had put a directional tyre on the wrong way and that the balancing was out. With this fixed I took to the motorway and shake had completely fixed itself - going up to 140 without any issue. However the breaking judder is still there..... :-(

Saw an American post and this guy stripped the wheel down to the hub and scrubbed it with wire wool till it was brand spanking new. At the same time he removed the screws which combine with the wheel nuts hold the entire assembly including tire in place (and scrubbed these too) - he claimed it fixed the problem but was wondering if anyone else has tried this? It seems like a lot of elbow grease for little reward!!! any thoughts welcome...

You say any thoughts welcome!!!! Maybe you should have thought about being a responsible person before taking your car to 140mph, especially with a brake judder ......the cause of which you have no idea. My thoughts are that you are a danger on the roads.