XSeries-forum

I know, I know there are thousands of pages here, Xoutpost and everywhere else on the dreaded judder when braking at speed.  Trouble is no one posts that its fixed and they are all years old.

Ive been experiencing on and off for about a year.  I replaced front pads and rotors and it seemed to subside for a bit but it returned after a couple of weeks.  Have just replaced the lower control arms which has made sod all difference, so now Im a bit stuck.

Opinions seem to vary as to whether the wishbone / hockey stick control arm contributes to the judder or if the ball joint that control arm bolts to can cause it?

Any suggestions where I should look next?

I poly bushed the control arms on mine and that fixed it. Solid now. My car has done 140k and it feels tighter than our other- which is exactly the same- and thats only done 70k.

funnily enough mines just coming up to 140K too.  Did you polybush both sets of arms and that fixed it?

I also read that cheap rotors arent great on these big machines but if it was a rotor warped or rippled surely it would be at all speeds not just from 55mph up?

No, just the forward big bushes. The lower ball joints were replaced as well as one was banging like mad.

Had this problem on mine and the brake callipers were sticking both were replaced problem solved

If nothing is sticking and all the bushes are good ive seen it come from the disc mounting face being slightly corroded or off flat and over time the disc being slightly off true means it gradually warps the disk.

A on hub brake disc skim will soon tell you if its that or not

Cheers chaps, Ill double check to see if anything is sticking, the front brakes seem to throw a lot of dust but I dont think thats unusual in these big cars.    Rob did your sticking calipers only cause trouble at high speed?

[quote="Nick73"]
I know, I know there are thousands of pages here, Xoutpost and everywhere else on the dreaded judder when braking at speed.  Trouble is no one posts that its fixed and they are all years old.

Ive been experiencing on and off for about a year.  I replaced front pads and rotors and it seemed to subside for a bit but it returned after a couple of weeks.  Have just replaced the lower control arms which has made sod all difference, so now Im a bit stuck.

Opinions seem to vary as to whether the wishbone / hockey stick control arm contributes to the judder or if the ball joint that control arm bolts to can cause it?

Any suggestions where I should look next?
[/quote]


There are actually lots of posts that declared it fixed, but the problem is that there is no single cause that is the same in and each and every case.
To name but a few, it could be tyre damage, wheel damage, wheel balance, warped discs, brake pads (as a root causing the discs to warp), sticking pistons in the callipers, control arm/thrust bushes, ball joints, etc etc etc etc ........

Cheers Smeeagain, I think you're right its a symptom of a dozen different things.  But... i keep thinking if it was brake related warped disks / sticking calipers etc it wouldn't only happen at high speeds surely (in my case at least)?  Im no mechanic so could easily be wrong : :blink:

anyway time will tell, thrust arms and ball joints on order

I have this but noticed it's only when I'm not smooth on the brake pedal or at higher speeds. Any ideas plz

Had the same.  As per above, could be down to one or more of a variety of things.

In my case it was tyres!  I didn't set out to resolve the issue, but merely had new tyres fitted.  From that point on the vibration disappeared!

PS: I only got the steering wheel shudder When slowing to say 50/60 - a good example being when leaving the motorway slowing onto the slip road.

Brewer

After changing the disks & pads I still had the judder around 60mph, replaced the brake reaction arms & it was all good.