Brakes - Steering Wheel Wobble

[jonobradley]

Hi Guys,

So got my Z3 3.0i a few weeks ago - all fab but I get really bad steering wheel wobble/vibration when I brake firmly anything over 40+ mph.

The front discs/pads/calipers were replaced by the previous owner 1000 miles ago, and they "look good/as new". After I had to brake hard for a crazy driver who wanted to not give way at a junction, my rear offside brake caliper partially seized until the next morning when it freed itself. Anyway rear brake discs/pads and calipers were rotten so I have just got them replaced. However I still get bad wobble/vibration from the steering wheel over 40mph when firmly braking.

Normally experience tells me the wobble from the steering wheel is from the front disks being warped or hairline crack. Any ideas? I have bought some new front Brembo disks and pads, but wondering if the tracking may need checked?....Although car rides lovely and smooth 70+

Any advice is hugely welcome.

 

[t-tony]

Money is on the front brake disc run out. If they're relatively new it's worth taking them off and checking that the hub flange is clean and flat (you can check that with a straight edge, ie steel ruler).
Also, if the disc hold down screw is missing/broken, make sure the screw hole is aligned with the broken screw if it is still in the hub.

Tony.

 

[andyglym]

Could be a number of things, check all your bushes on the suspension as a start. These cars are susceptible if all is not in good order, bushes, tyre pressures, wheel balancing.

 

[jonobradley]

Brill thx Tony, will check hopefully in next few weeks when I get back from work

 

[jonobradley]

Could be a number of things, check all your bushes on the suspension as a start. These cars are susceptible if all is not in good order, bushes, tyre pressures, wheel balancing.

Thx new poly pushed and links put in last year for previous MOT, new tyres and pressures good, as per Tony will check discs and hubs for starters also

 

[NZ00Z3]

Jack up each front wheel in turn and check the tie rods. That is the 3 to 9 o'clock wobble test.

 

[t-tony]

Brakes will pick up on play in bushes etc. but it is always disc run out which "sets the wobble off" in the first place. Otherwise you would get it without any brake application.

Tony.