Suspension groans

[bruce.g.cameron]

I had an almost-consistent groan, that I'm having a hard time diagnosing. Sounds like rubber on metal, if I had to guess.

It is very loud inside + outside the car. I have induced it from steering (groan as you turn lock to lock) and from driving over bumps at low speed. It doesn't seem to appear at high speed, even when going over substantial bumps.

I was under the car listening for it, with my wife turning the wheel lock to lock while car was jacked up - therefore it makes noise even when the suspension is not loaded. I thought it was definitely steering, but I couldn't find it while under there. Didn't seem to be the idler arm, or that horizontal damper in the steering.

My best guess is that it is the strut mount, but I don't know how to test for it. Doesn't seem to happen when I bounce the car in the driveway.

For reference, strut mounts, front struts were done 15k miles ago. Steering was rebuilt 30k miles ago, inc. ball joints, tie rods, etc.

Any thoughts?