Modified calipers? Someone has modified standard calipers to make them accept 330mm discs? Have you got a picture? Depending on the bracket you may find the caliper is flexing under load. I have had warped discs and got a gentle wobble rather than a dash shake.

Look at the discs to see if there's an unusual wear pattern. Fix something very close to the disc and spin the disc keeping an eye on the gap to see if they are warped in any way.

I reckon it's a caliper issue though.


Charlie