Can worn rotors cause noisy clunking against pads?

[pierremcalpine]

Alright experts, I still can't figure out the source of my front end clunking. So let me ask you, if my rotors were worn right down to minimum thickness (exact minimum thickness to be precise - 21.70mm) and if there was a ridge on the inside and outside of the said rotor is it possible that the pads could regularly catch on the ridge and make a soft clunking noise that would be audible in the cabin that can be felt primarily when taking off slowly from a stop?

[druid]

Originally Posted by pierremcalpine

Alright experts, I still can't figure out the source of my front end clunking. So let me ask you, if my rotors were worn right down to minimum thickness (exact minimum thickness to be precise - 21.70mm) and if there was a ridge on the inside and outside of the said rotor is it possible that the pads could regularly catch on the ridge and make a soft clunking noise that would be audible in the cabin that can be felt primarily when taking off slowly from a stop?

Yeah why not! We know the rotors get bad edges, might be that.

[ww1dm1]

I'm no expert, but I'd say it's far fetched if the clunk only happens on the moment of takeoff. Pads should be worn according to the rotor shape as well. I'd lean towards the engine mounts, DMF, axles, CV joints, possibly gearbox/differential. You could play around with the wheels lifted if you have strong reasons to believe it's the brake discs.

[pierremcalpine]

Originally Posted by ww1dm1

I'm no expert, but I'd say it's far fetched if the clunk only happens on the moment of takeoff. Pads should be worn according to the rotor shape as well. I'd lean towards the engine mounts, DMF, axles, CV joints, possibly gearbox/differential. You could play around with the wheels lifted if you have strong reasons to believe it's the brake discs.

Yeah, regretfully I'm inclined to think you are right. Thing is I've replaced all the other things I could possible replace short of the tranny itself! It really doesn't feel like it's coming from the tranny either. Feels like the noise is further to the outside.

[ITSv40]

If the brake discs are as worn as you say, they need replacing anyway. Fit new discs and pads and if the noise disappears then you know you have cured it, if not keep looking.

[SIAMBLUE]

Have you checked to see if your sliders are all working as they should ?

[pierremcalpine]

Originally Posted by SIAMBLUE

Have you checked to see if your sliders are all working as they should ?

Yep, sliders working.

[pierremcalpine]

Originally Posted by ITSv40

If the brake discs are as worn as you say, they need replacing anyway. Fit new discs and pads and if the noise disappears then you know you have cured it, if not keep looking.

Yeah, I suppose you are calling out the obvious...I just feel like I've spent as much as I'd like to spend on this car this year and the pads have tons of life left. Was hoping to just change it all out in 2018. Rotor thickness currently stands at 21.70 and 21.90 with minimum rec'd at 21.70.

[NTG]

I thought that the brake rotors could be worn down up to 18mm (ventilated rotors). The new ones come come with 24 mm and the Volvo papers that come with it says that they should be replaced at 18mm.

[ITSv40]

Originally Posted by NTG

I thought that the brake rotors could be worn down up to 18mm (ventilated rotors). The new ones come come with 24 mm and the Volvo papers that come with it says that they should be replaced at 18mm.

Minimum thickness is 21.5mm, 22.1mm if new pads are to be fitted. 8mm for rear discs.