Tracking mysterious single pop/clunk SOLVED

[Erickk120]

rebuilt entire front end aside from, CV axles/Hubs, as they were tight and had no play in any axis, I even did control arm bushings and camber/caster kits. Lower control arms look fine, I've gone back and retightened just about everything to spec, I even torqued the front and rear cross member, I can't seem to find what's causing it, I notice this sound when I turn on uneven roads and the weight shifts to 1 side or the other,it does it in right or left turns, as long as it has the right amount of momentum never does it going straight or during bumps, I can feel it around the floorboard area in the driver side I do not feel it in the steering wheel, I've checked the body mounts but they seem to be in good shape and tight. The only part I have yet to check thoroughly is the torsion bars cross member mount bushings, I gave it a quick look this morning and noticed that I can move the cross member up and down with a little bit of effort using a 2 feet pry bar, are bushings suppose to move like that? also noticed what seemed to be a piece of rubber coming off, couldn't tell as it was dark, but seemed like its coming apart. Could this be the noise that is hunting me? I never noticed this noise before I got work done in my suspension, so could it be that everything was so loose that now that everything is tight, all that play is gone in the front and it's multiplying at the cross member area?

This sound has really been bothering any ideas on what could it be...

 

[Scottydoggs]

ive heard of the torsion bar cross member coming loose before. might want to see if you can tighten it up. the bolts might be fubared tho from any rubbing they might have been doing.

 

[SnowDrifter]

If you get outside the car and rock it back and forth, does it make the same noise?

 

[Erickk120]

If you get outside the car and rock it back and forth, does it make the same noise?

I've tried but not with much force, will give that a shot with my entine weight. Now that I think about it, when I was doing my uca bushings I noticed a similar pop sound when I was either jacking it up or down I can't really recall, I had the driver side uca done and I was about to do the passenger side, I didn't think much of it back then, but thinking about it now that sounded a lot like this ghost am chasing. I jacked it from the front frame area where the lower control arms attach to I believe, I will have some free time tomorrow to see what I can find. Any specific area I should look for as I heard it once when loading unloading the suspension.

 

[SnowDrifter]

Anything that moves or pivots. I know that's not particularly helpful, but if you can replicate the noise with the vehicle at a stop it will make the diagnostic process much easier. Just grab a second person

 

[Erickk120]

I will check tomorrow hopefully, if I dont find anything loose/worn anywhere, I suspect it will end up being the following tsb, as it is exactly what I'm experiencing.

#06-08-61-003D: Underbody Pop or Clunk Type Noise While Turning or Driving on Uneven Road Surfaces (Install Body Mount Insulator) - (Sep 10, 2008)

Subject: Underbody Pop or Clunk Type Noise While Turning or Driving on Uneven Road Surfaces (Install Body Mount Insulator)

Models:
2004-2008 Cadillac Escalade, Escalade ESV, Escalade EXT
2004-2008 Chevrolet Avalanche, Suburban, Tahoe
2004-2008 Chevrolet Silverado (Classic), Silverado
2004-2008 GMC Yukon, Yukon XL, Yukon Denali, Yukon Denali XL
2004-2008 GMC Sierra (Classic), Sierra Denali (Classic), Sierra, Sierra Denali

This bulletin is being revised to update the model years and include diagnosis information. Warranty information has also been updated. Please discard Corporate Bulletin Number 06-08-61-003C (Section 08 - Body and Accessories).

Condition
Some customers may comment on a pop or clunk type noise while turning or driving on uneven road surfaces. This noise can be heard and/or felt at either the driver's or front passenger floor pan area.

Cause
Under certain conditions, normal movement between the frame and the #1, #2 or #3 body mounts may cause this noise to occur.

 

[Erickk120]

UPDATE:
In case any of you ever experience this problem, It turned out that the TSB listed above was correct.
Installed 1 insulator in the first 2 body mounts of each side in the front, and also double checked the lower control arms, torqued them to 130 ft lbs and they needed that tiny bit more I was able to move the nut 1/3 of a turn for each one. Checked everything else under it and retorqued all the body mounts to spec.
Went for a short test drive, took a few aggressive turns and nothing, just the typical tire squeal from heavy trucks when you abuse them .
I was so glad it was over, that I decided to get happy feet and did a short sweet burnout for my victory!
Total for the fix was $25 after shipping for 4 insulators, a pretty cheap fix for what could have been a nightmare just throwing money at it and replacing good parts.
I never had this problem before I worked in my suspension maybe because everything was so worn that it absorbed it who knows.
Now I just need to find that squeak in my trim molding in the dash Jk~!
here is a pic of where the insulators are placed.

 

[SnowDrifter]

How tough was the install?

Never fussed with body mounts before. Need a jack?

 

[Erickk120]

How tough was the install?

Never fussed with body mounts before. Need a jack?

It wasn't too bad, once you loose the old mounts you are set. You just need to cut the isolators to shape for it to fit around the base of the bushing.