Clunking noise under front passenger side...help!

[chrisfuture8]

Hello All,

This is my very post to this forum and I hope I can get some helpful suggestions/info from someone who's knowledgeable with the front suspension or has experienced this problem before.

This 2002 X5 4.4 with a 130K miles is (well, was) my wife's daily driver until everything that can go wrong started going wrong.

I'm not new to BMW (I actually owned 3, 5 series in the past and now has an 850 for 10 years) and have been working on them for about 10 years now.

On this X5, I have done a long laundry list of R/R since the beginning of the year. Some of the things I have done were:

1: Upper timing covers resealed
2: Valve cover gaskets replacement
3: CAM sensors replacement
4: New spark plugs
5: Timing chain tensioner replaced
6: New tires
7: New sway bar links
8: New upper control arms
9: New driver's door handle
10: New fuel pump
11: New fuel filter
12: Recent coolant expansion tank replacement
13: New front passenger wheel axle
14: Rebuilt driver's side wheel axle with new CV boots/grease
15: etc, etc.

After I replaced the upper control arms, sway bar links, and axles, I partially tighten the bolts and set the car level on the ground to put proper load on the suspension. I then proceeded with fully tightening the axle nuts, and suspension component bolts/nuts.

When I drive on city streets I hear these loud clunking noise underneath the front passenger side. I can't make out what it is and everything seems tight.
On the freeway and at speeds in excess of 65mph, I don't hear the clunking noise...it seems smooth and quiet. Any speeds lower than that and especially around surface roads, the noise is quite obvious.

What have I missed and has anyone experienced this before? I also want to mention that I actually replaced the torn CV boots on both axles where the old grease was cleaned off and new grease added. Due to the noise on the front passenger side, I thought perhaps the CV joint has gone bad so I went and replaced OEM wheel axle just about 30 minutes ago and took the SUV for a test. Didn't change anything...still that noisy clunky sound.

Could the removal and re-installation of the support plate underneath the engine be a culprit? I have removed it before and never had the problem. Reason why I ask is because the sway bar moves freely when the plate is removed and when installed, perhaps the sway bar is misaligned and twist...?

Hoping someone with suspension knowledge can share some ideas.

Thanks.

[Delta2nineR]

Sounds like control arm bushing. Very very common. I replaced mine 2 years ago and they're shot again. Some people on here reckon that my mechanic didn't drop the car off the jack before applying final torque on bushing nuts hence the failure again.


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[andrewwynn]

If it's rapid taping eg every little bump it's almost certainly the sway bar link which you mentioned being replaced.

The next choice as mentioned are the various bushings holding the control arms.

If the wheels shift fromt/back from brake application it's the thrust arm bushing.

If none of those the bearing at the top of the strut can be the cause but it's under spring pressure always so not too likely.


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[chrisfuture8]

Thank you Delta2nineR and Andrewwynn for the suggestions. The front suspension had bad upper control arms (these are called thrust arms correct...?) so I replaced them at the same time I R/R the wheel axles and sway bar links. The sway bar links rubber boot were cracked badly so it was time for replacement.

Prior to replacing these components, the front lurched forward when braking. Looseness in control when going into parking lots. After replacing the upper control arms, the front feels solid although it veers to the right a little more than before (need to take it in for front wheels alignment after the suspension work).

I checked the bushings on the lower control arms last night when replacing the wheel axle and they look good. No cracks or tears anywhere yet. The type of clunking noise that I'm hearing now was not there even before the replacement of worn suspension parts up front.

I am also leaning towards the sway bar links and bolting of the sway bar to the support plate.

Thanks.

[andrewwynn]

There is a rubber bushing that holds the anti sway bar.. if that has slop you will get a terrible clunk. I know this first hand from driving a few miles with my sway bar unattached. Wow that was noisy!

If something was misalligned your sound could easily be there.

If deeper thump look toward the larger bushings : front side or back (sway bar). If higher click sound look at the small joints like sway bar link.

If sway bar link you can tightly wrap with electrical tape and the sound will go away.

[chrisfuture8]

"If deeper thump look toward the larger bushings : front side or back (sway bar). If higher click sound look at the small joints like sway bar link."

It's hard to put it into words but the clunking noise sounds like one part tapping/rubbing against something else when the front passenger wheel moves up and down. Most obvious when going over any irregularities on the road.

"If sway bar link you can tightly wrap with electrical tape and the sound will go away."

Wow, this I did not know.

I will give another thorough inspection later this evening. While I had the front jacked up last night, I tried moving and pulling the wheel side to side and front to back and there was no play that I could feel. So it may be safe to say the bushings on the upper/lower control arms are okay.

[svvg]

On mine it was the ball joints. Have rebuilt one side but the other side is still in bits (had to remove the hubs in order to smash the ball joints from above with a 4lb hammer and a two foot cold chisel....).

It doesn't look like there’s enough access to tighten the bolts with the wheels attached - so I was going to jack the hubs up directly??? How did you manage it?

[andrewwynn]

Oh: looks can be very deceiving. Consider this: there is 1200# of pre-tension on each front corner and realize that no human input will do much to influence that.

There are ways to remove the spring tension to help determine what is loose but "looks good" didn't really apply to bushings. By the time they don't look good they have been destroyed for quite some time


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[andrewwynn]

You should be able to get to any of the suspension nuts to final tighten on the ground but you can use a jack to lift the corner without a wheel on watch YouTube videos to see examples. I have to do ball joint and front thrust bushings on mine and wife's cars. I may drive up onto a half cement block to give myself a little more elbow room.

[chrisfuture8]

Originally Posted by svvg

On mine it was the ball joints. Have rebuilt one side but the other side is still in bits (had to remove the hubs in order to smash the ball joints from above with a 4lb hammer and a two foot cold chisel....).

It doesn't look like there’s enough access to tighten the bolts with the wheels attached - so I was going to jack the hubs up directly??? How did you manage it?

I had the brake caliper off and removed the rotor from the wheel hub. It was all necessary anyway because of replacing the wheel axle(s). That gave me enough room to work with the arms.