I had this similar problem on my 3.0/01 X. Loud clunk sometimes over bumps, sometimes not. Mechanic said, thrust bushings, but they were freshly pressed new just 24K miles ago, he said, have to do the entire part. OK, but guess what; still clunked. It turned out to be upper strut bearing on the driver side. I figured, we didn't replace them when we did front strut pair at 160k miles. The clunk started at 188, shortly after replacing both front axles with new OEM. Good luck. BTW, struts original? Axles don't typically clunk, they tend to rattle loud when the CV joints are going. The ball joint and lower control arms make a fairly loud clunk when stopping short or pulling out in reverse and braking hard. You are literally lifting the front end on reverse hard braking. Try it.

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X5 3.0 AUTO -2001 - 238,000 miles