Shutter when braking at high speed

[MileHighIX]

Hey all, my '90 325ix shutters under braking at highway speeds. The vibration feels like its coming from the rear but hard to tell. I figured it was rotors but a friend suggested drive shafts or trans mounts. Anyone have a similar experience and can tell me how they resolved the issue? Can you help point me in the right direction on how to diagnose the issue? I was hoping for suggestions before I just start throwing parts at it. Getting new pads and rotors wouldn't be a bad thing but I'm trying to keep running cost down. Its just my winter beater, not a pristine e30


And before you flame me I did do a search and couldn't find any related threads..

Thanks in advance!

[Chrisbike]

It’s most likely warped brake rotors if it’s happening when braking. If you want to keep cost down you can turn down the rotors (if you have room to) and replace the pads.

[Max325ix]

It is most likely a warped rotor however, can also be a caliper that is sticking. That was the issue on my 1988 E24 M6. 50miles+ on the highway, when breaking it shuttered including in the steering wheel.

Max