Hi

my car steering vibrate when doing 70mph and vibrates when breaking. changed the pads and disk but results still the same. could it be wheel balancing? tryes are fairly new and 6 months back had 2 front wheel bearing done. when i brake sometimes you hear grinding noise but it breaks fine. any ideas please?

If it is vibrating when just driving along and only at higher speed for me balancing is the first thing I would have checked. As wheels were done recently you could look to see if there are any marks where any weights may have fallen off. I assume it didn't do it immediately after getting new tyres?

Could it be the rears rather than the fronts?

You'd be surprised just how well the vibration can be passed through a car body.

could also be slack wishbone bushes, but balancing would be my bet

I had a faulty calliper on a previous car that would warp a disk over the course of a month. Took a few disks before it was picked up and fixed. But the problem was 'fixed' until the new disk was warped again. If the problem never went when you change the disk I doubt it was that disk at fault.

Vibration whilst braking suggests warped front brake discs to me, especially with the occasional grinding noise. I would have the discs checked, if they are new discs and out of true then they will be covered under the terms of a parts warranty.

Mike

Sorry mike that is not true, there is many reasons that a disc could be out ou true (warped). I used to do alot of warranty returns for partco/unipart and used to get people trying to claim warranty's on new disc that were warped when the whole breaking surface was blue with overheating. But the OP has said he has changed the discs and pads and the problem is still there. I have heard of vibrations on cars at speed caused by the large grub screw thingy that screws the disc to the hub being missing causing the problem. My money is still on the wheel weights.

My Nissan Primera didn't even have front brake disc retaining screws.Not even any hole drilled for them .They were held on by the wheel after fitment.

Wheel balancing almost certainly and you'd be suprised how little it has to be off to make this happen. Mike's suggestion that the mating faces be checked is a good one as well. I assume these are standard wheels not ebay junk with the wrong centrebore or something?

Check the wheel nuts are done up tight!