2.4 Tourer Auto (2004 vintage)
Now before everyone auto defaults to discs this is what I have done so far:
TRW Discs/Pads all round around March 2017, both new rear calipers (old ones had seized) at the same time. Everything was fine until a few months ago when I started to notice vibrations under braking, progressively got worse and now shakes the whole front end. All the hub faces and mating faces when I did the brake job were spotlessly cleaned so everything is sitting on a good surface (disc to hub, wheel to disc).
I have been under the car and crow barred all the mounts and bushes front & rear, all seem solid to me. Replaced both front wishbones complete as front bushes were deteriorated and I thought this could be the cause, no change.
Taken apart front brakes, verified front caliper pistons is sliding in and out smooth and the front pins are not seized, cleaned everything again and re-fitted.
Taken apart rear brakes, verified rear caliper pistons are sliding in and out smooth and all slider pins are not seized, cleaned everything again and re-fitted.
Front & Rear wheel balancing is done and no issues with wheels or tyres (16").
Wheel alignment is fine.
Disc runout with DTI:
Both front= 0.02mm
Both rear= 0.04mm
Service limit= 0.1mm
Checked all wheel bearings for roughness and play, nothing found.
Checked Tie rod ends, ball joints, drop links (replaced during wishbone replacement), coil springs.
None of the shocks are leaking or showing any signs of failure.
All CV joints feel fine at the front.
I am at a loss and its doing my head in. Car drives smooth and in a straight line, no vibrations on normal driving at high speeds whatsoever. As soon as I touch the brakes the front shakes/shudders pretty bad. Feels like whole front end and steering wheel all at the same time. Braking from 70mph feels like my teeth are going to fall out, its bad enough that I see distortion on the speedo needle like its out of focus. Braking from about 40mph you can visibly see the steering wheel wobble side to side about 5mm defection. I would have thought something worn this bad I would see it when poking around with a crow bar.
Any ideas? anything else common on these on the front end that can wear and cause my symptoms? My brain is going toward a balancing problem on the front discs even though the runout seems fine could they just be out of balance already?
Typically if anyone verbally talked to me about a problem like this I would say front discs if it only happens when pressing the brake pedal and no other signs of a seized caliper/pins but I've checked it all and this is where I am.
Thanks for input.