When I bought and first drove my 530i, I noticed a severe steering wheel shimmy around 45-55 mph, 75 mph, and during braking.
I ruled out warped rotors as the primary cause since the worst vibrations occurred during driving. I decided it was one or all of the front arms or unbalanced wheels causing shudder. I highly doubted the previous owner performed any preventative maintenance and I was right, all the suspension pieces were original and have never been changed out.
I switched out the old lower front control arms with Lemforder arms and a large majority of the shimmy went away. The really bad 45-55 mph wobble was gone but the higher speed vibrations remained. After switching out the thrust arms all shimmies are gone and the 530i drives great.
