Brake judder at specific speed

[Hammy98]

Hi guys,

Looking for ideas here as I'm having conflicting thoughts on what the issue could be here.

I'm getting steering wheel vibration on my M5 which starts fairly lightly at 85 and gets more prominent as speed increases.
I've also noticed that I get a similar steering vibration (accompanied by brake pedal vibration) if I apply the brakes between 45 and 55 - braking above this range is smooth, as is braking below it.

Initially I thought warped discs due to the braking vibration, but I don't think that would cause the steering wheel vibration when cruising at higher speeds. When I've had that previously it's been wheel balancing.

What do we think, unrelated issues? Tracking maybe?
Car's only done 40k so thinking it wont be bushes or arms.

Cheers

[d_a_n1979]

Thrust arms bushes failing/failed IMO

Get the car up on the ramps and inspect the suspension arms/bushes and ball joints ASAP

It could also be caliper related; but generally it's suspension

[Mave]

Agree with the suspension diagnosis. BMW suspension bushes aren't particularity long lasting 😭

[helix402]

Start with getting your front wheels balanced.

[bennno]

helix402 said:

Start with getting your front wheels balanced.

Right answer, this first.

[Hammy98]

Had the wheels balanced last night, high speed vibration is gone but they did note a really small buckle on the offside front.
The guy was adamant I wouldn't be able to feel it but going to have it sorted anyway.

The braking vibration now feels a bit worse... can feel it under light braking from 50 upwards.
If I'm hard on the brakes it feels smooth - very odd.

[bennno]

Hammy98 said:

Had the wheels balanced last night, high speed vibration is gone but they did note a really small buckle on the offside front.
The guy was adamant I wouldn't be able to feel it but going to have it sorted anyway.

The braking vibration now feels a bit worse... can feel it under light braking from 50 upwards.
If I'm hard on the brakes it feels smooth - very odd.

Change disks and pads then.

[d_a_n1979]

Hammy98 said:

Had the wheels balanced last night, high speed vibration is gone but they did note a really small buckle on the offside front.
The guy was adamant I wouldn't be able to feel it but going to have it sorted anyway.

The braking vibration now feels a bit worse... can feel it under light braking from 50 upwards.
If I'm hard on the brakes it feels smooth - very odd.

That could be pad deposits... Try some hard but safe braking, like you're bedding the pads in again and then see how they are after that

But if your pads have worn unevenly; there's no fixing that, new pads needed (ideally with new discs)...

Don't cheap out on brake parts; cheap parts are cheap for a reason

Stick with OEM BMW or the OE makers (TRW, Textar, Jurid and ATE)

[Hammy98]

d_a_n1979 said:

That could be pad deposits... Try some hard but safe braking, like you're bedding the pads in again and then see how they are after that

But if your pads have worn unevenly; there's no fixing that, new pads needed (ideally with new discs)...

Don't cheap out on brake parts; cheap parts are cheap for a reason

Stick with OEM BMW or the OE makers (TRW, Textar, Jurid and ATE)

Will try bedding them in again, cheers. Hoping it could be that.

Always reluctant to start throwing parts at it unless they're confirmed to be at fault, pricing up discs and pads for the front is looking like 1.2k. Wouldn't risk non-BMW parts, been there before and they never perform as well as OEM.

[Hammy98]

d_a_n1979 said:

Thrust arms bushes failing/failed IMO

Get the car up on the ramps and inspect the suspension arms/bushes and ball joints ASAP

It could also be caliper related; but generally it's suspension

Will get it this checked over next if it's not pad deposits. Cheers

[d_a_n1979]

Hammy98 said:

d_a_n1979 said:

That could be pad deposits... Try some hard but safe braking, like you're bedding the pads in again and then see how they are after that

But if your pads have worn unevenly; there's no fixing that, new pads needed (ideally with new discs)...

Don't cheap out on brake parts; cheap parts are cheap for a reason

Stick with OEM BMW or the OE makers (TRW, Textar, Jurid and ATE)

Will try bedding them in again, cheers. Hoping it could be that.

Always reluctant to start throwing parts at it unless they're confirmed to be at fault, pricing up discs and pads for the front is looking like 1.2k. Wouldn't risk non-BMW parts, been there before and they never perform as well as OEM.

You don't need to stick with BMW parts unless you really want to; as already mentioned the OE makers I've stated above

You'll find those parts via Autodoc for aroujnd half of what BMW will charge you; but it's your car/your wallet etc

However, try Cotswolds BMW for a quote on parts as well as the likes of Douglas Park BMW on eBay - use www.realoem.com to find the part numbers etc

[plenty]

I had a persistent judder on my Z4M braking from 55-60. It was a sticky NS caliper.

[Aluminati]

d_a_n1979 said:

You don't need to stick with BMW parts unless you really want to; as already mentioned the OE makers I've stated above

You'll find those parts via Autodoc for aroujnd half of what BMW will charge you; but it's your car/your wallet etc

However, try Cotswolds BMW for a quote on parts as well as the likes of Douglas Park BMW on eBay - use www.realoem.com to find the part numbers etc

Dan has a google,….. yawn…

[Mr Tidy]

Aluminati said:

Dan has a google,….. yawn…

Maybe it's past your bedtime.

[d_a_n1979]

Mr Tidy said:

Aluminati said:

Dan has a google,….. yawn…

Maybe it's past your bedtime.

Haha he's a miserable git eh

[Hammy98]

Went to get the buckled wheel repaired but once they got the wheel onto their jig, they realised it’s actually a high spot on the tyre.

Had this once already with these standard fit Pirelli P Zeros, and since the backs were already getting low I’m going to switch over to Michelin PS4S.

Hopefully that will be it resolved.

[Hammy98]

Got this sorted for anyone interested...

Vibration off brakes was resolved by new tyres (Pirelli are crap).
Vibration on brakes was some really stubborn pad deposits. The regular emergency stop from 70-20 numerous times didn't sort it. Upping the speed to 120ish on a private road and repeating 6-8 times managed to clear them. A lot of my driving is up and down the motorway to work during rush hour so I reckon the deposits had some time to harden making them more difficult to clear.

Glad I tried bedding them in again before going for discs and pads!

[d_a_n1979]

Hammy98 said:

Got this sorted for anyone interested...

Vibration off brakes was resolved by new tyres (Pirelli are crap).
Vibration on brakes was some really stubborn pad deposits. The regular emergency stop from 70-20 numerous times didn't sort it. Upping the speed to 120ish on a private road and repeating 6-8 times managed to clear them. A lot of my driving is up and down the motorway to work during rush hour so I reckon the deposits had some time to harden making them more difficult to clear.

Glad I tried bedding them in again before going for discs and pads!

Good to see you're all sorted pal

[Hammy98]

d_a_n1979 said:

Good to see you're all sorted pal

Thanks mate, appreciate the advice

[d_a_n1979]

Hammy98 said:

d_a_n1979 said:

Good to see you're all sorted pal

Thanks mate, appreciate the advice

No worries; pad deposits can be a sod at times, more so if they're on the inner face rather than what you can see