I have had my steering swap done for about a week now, and even before I did this I was able to hear a plastic-ish thump over some larger bumps on the road. It doesn't have the ring of a balljoint, and steering stuff completely swapped changed nothing. And unlike a balljoint, the sound trails off like a spring "ing'ing" downward after the initial blow.

Splash pan on or off doesn't change it.

You didn't say front or rear. If rear, check exhaust and trunk area for looseness and banging. I get a similar sound occasionally from the rear of my car after going over bumps. Haven't found it yet, but I suspect exhaust banging in back - maybe axle?

If in front, I'd look at everything. Mounts, bushings etc. Do you hear or feel it when braking or making a hard, slow turn on an incline?




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90 244DL 1/4 million miles - original engine/drivetrain :)

I had something similar that turned out to be a loose shock absorber nut on one of my front struts. Not loose enough to notice it by just looking, but loose enough for the shock to have play in the strut.
good luck!