Single clunk noise under the car?
 

Hi everyone:
I need help to narrow down an annoying single clunking sound from somewhere in the middle (and possible in the back?) under my car. From more than a year, I am experiencing this clunking noise especially when:
1. Mostly when I turned left or right. I can easily reproduce the single clunking noise when I turn from the street to go up to my driveway. or going down from my driveway turning into the street.
2. Going straight then slow down/braking before a turn.

There is NO clunking noise when I accelerate, brake, or going straight (even on a bumpy road). I noticed the clunk noise only happened when there is a shift/twist of the car weight from one side to the other. My indie checked all the 2-3 flex disks from the drive shaft and they are ok. He does not think the sub-frame bushings are bad either.

my car: 05 X5 3.0L, no air suspension.
Thanks!

Check the lower ball joints.

And then check the torque on the six reinforcement plate bolts.... The give away here is the noise occurs when the chassis is experiencing twisting or flexing forces.

Look at sway bar links. Those tend to go bad and can give you that "clunk". Luckily its a cheap simple repair.

Thanks for the replies! Other than the plate's bolts, which are easy to check, how do you check for bad ball joints? can I assume that the ball joints are in the rear of the car since I don't have any steering looseness or vibration in the front suspension?

Single Clunk RESOLVED!
 

Thanks so much to upallnight, wpoll, and smokeyyank! After many long desperate months, the clunk noise is now resolved!

I actually got both problems that you mentioned:
1. One of the front bushing in the tension bar - driver side was completely shot. I replaced it. I also replaced the driver side since the bushings got serious cracks
2. Two bolts from the re-enforcement plate were loose, one from each side. They were the ones that also held the torsion bar - right above the plate. I think the majority of the clunking was from these two bolts

My car now drives so smooth, quiet, and solid, without any clunk!

:thumbup: