I'm at a loss... Can't determine CLUNK sound

[GranPrix]

17 Tahoe LS with 140k. The suspension has been making a clunking sound front and rear. It was due for a full front and rear end suspension refurb so it has new:

New hardware
New Upper and Lower arms front and rear
Panhard bar
Front and rear factory shocks
New front spring upper seat
New spring insulators
New upper shock mounts
New strut bumpers
New rear upper insulators
Swar bar mounts and links new

Pretty much every component has been replaced new with OEM parts and I'm STILL getting the clunk. Sound only happens on bumps and road imperfections at slow and high speeds. Anyone have any ideas

 

[mrkev]

how does your car idle? Could it be motor mounts? Try to isolate the bump by doing things like pressing on the brakes/accelerating/decelerating/coasting/engine-loaded or not

for example, when you are about to hit the bump, drag your brakes a little. This will put tension on the calipers and rotors to rule those out. Could also be Bearings, but that would make a howling sound. and could be something simple like a nut that wasn't tightened. This happened to me before. a bolt on the lower control arm was on, but night tightened.

 

[LegalBrief]

Sound travels… where you hear it may not be where it’s coming from.

Sway Bar, Sway Bar Bushings, End Links, Ball zjoints, Tie Rods are all common Kline’s, especially at 140k

 

[Joseph Garcia]

Check your front differential mounts.

 

[GranPrix]

how does your car idle? Could it be motor mounts? Try to isolate the bump by doing things like pressing on the brakes/accelerating/decelerating/coasting/engine-loaded or not

for example, when you are about to hit the bump, drag your brakes a little. This will put tension on the calipers and rotors to rule those out. Could also be Bearings, but that would make a howling sound. and could be something simple like a nut that wasn't tightened. This happened to me before. a bolt on the lower control arm was on, but night tightened.

After posting last night, I thought about the engine mounts. They’re less than a year old but maybe they weren’t torqued down enough. The hubs are still good and all the bolts were checked.

 

[GranPrix]

Check your front differential mounts.

RWD

 

[GranPrix]

Sound travels… where you hear it may not be where it’s coming from.

Sway Bar, Sway Bar Bushings, End Links, Ball zjoints, Tie Rods are all common Kline’s, especially at 140k

Like I stated in the original post, all of those items are new

 

[Fless]

Transmission mount worn or loose? All crossmember bolts tightened to spec?

 

[GranPrix]

Transmission mount worn or loose? All crossmember bolts tightened to spec?

Yup, and it’s new also

 

[GranPrix]

Double checked and everything is tightened up. All three mounts are good.

The only other thing I can think of is the driveshaft/Ujoints. I do have some play on the shaft as I turn it… but not forward or backwards

 

[ss4chad]

I have this 'Clunk' sound/feel as well. I can step on the brake and give it gas and I can make the clunk come alive at will, so I was thinking Trans or Motor mount. I had previously thought it might be the rear shocks but I replaced those and the pads & rotors couple of weeks ago and it still does it.

I gotta change the trans fluid soon, while I am under there I'm gonna put a jack on the tail of the tranny and try to lift it up, then do the same with the left side engine mount and see if either are broken. If neither are broken then I'm not sure what it could be.

Chad

 

[GranPrix]

I have a feeling my clunk is the alignment pins that have decided to remove themselves from the chat group… FML

 

[JGman]

Did you get this issue solved? I just finished converting my 2011 XL from stock rear springs to air bags (stock height) due to my wife's bad back. The stock height conversion is working well and took the sharpness out of the rear. Things were fine for a couple of days, then, a clunking sound! I do all my own fabricating, so, I have to fix my own problems! Couldn't find anything loose. I finally tightened the spare 1/4 turn more. End of clunking.

 

[ss4chad]

I have a feeling my clunk is the alignment pins that have decided to remove themselves from the chat group… FML

Alignment pins?

Chad

 

[GranPrix]

So it seems I was correct. One of my alignment pins on the passenger side apparently decided it was no longer going to work and fell off. So now I no longer have that clunk sound. Which then caused the other one to inevitably do the same. I ordered some pins and a set of new alignment bolts and guides from dirtking. And the guides are great because it doesn’t allow for any movement, but the pins are horrible so I ended up getting some grade 8 bolts instead of using pins. Obviously alignments from now on are going to be a pain in the ass, but at least I don’t have to worry about losing the pins anymore.

Now the one thing I’m worried about is hitting a pothole or anything that might change my alignment. If this happens, I’m hoping the bolt that’s replacing the alignment pin shears off. But with a grade 8 bolt I don’t know if that’ll happen so now I’m debating as to whether or not to go with a grade 8 bolt.

 

[ss4chad]

Please elaborate!
Are you talking about the bolts in the Upper Control Arms (forward & Aft) that go thru the Alignment Adjuster Cam and bolts the Upper Control Arm to the Truck?
Your saying one or more of those Bolts/Pins broke?

Chad

 

[89Suburban]

Now the one thing I’m worried about is hitting a pothole or anything that might change my alignment. If this happens, I’m hoping the bolt that’s replacing the alignment pin shears off. But with a grade 8 bolt I don’t know if that’ll happen so now I’m debating as to whether or not to go with a grade 8 bolt.

I don't think you have anything to worry about in that regard.

Please elaborate!
Are you talking about the bolts in the Upper Control Arms (forward & Aft) that go thru the Alignment Adjuster Cam and bolts the Upper Control Arm to the Truck?
Your saying one or more of those Bolts/Pins broke?

Chad

Here are a few pics of the pins and locking cams from when I installed on mine.

What did you do to your NNBS GMT900 Tahoe/Yukon Today?

I’ve been putting this off, but finally dropped my oil pan and replaced the O-ring and gasket. Not the worst job to do, but not much fun either. That said, now my oil pressure is nice and solid in the green. I was getting intermittent low pressure warnings prior.

www.tahoeyukonforum.com

 

[Big Mama]

Please elaborate!
Are you talking about the bolts in the Upper Control Arms (forward & Aft) that go thru the Alignment Adjuster Cam and bolts the Upper Control Arm to the Truck?
Your saying one or more of those Bolts/Pins broke?

Chad

I believe so

 

[mountie]

I believe so

Referring to a previous post..... Considering the 'clunk' was there before you did all your replacements, ... Check your spare ??
Or maybe an exhaust pipe or muffler mounts?

 

[ss4chad]

I don't think you have anything to worry about in that regard.




Here are a few pics of the pins and locking cams from when I installed on mine.

What did you do to your NNBS GMT900 Tahoe/Yukon Today?

I’ve been putting this off, but finally dropped my oil pan and replaced the O-ring and gasket. Not the worst job to do, but not much fun either. That said, now my oil pressure is nice and solid in the green. I was getting intermittent low pressure warnings prior.

www.tahoeyukonforum.com

I have a hard time believing those small 1/4" (guessing size) pins would make a truck have a clunk to it. Now if the bolts that go thru that adjustment cam that you turn to adjust the alignment broke, I can see where a Clunk might be present. Those bolts are secured (tightened) as tight as crap so that the alignment stays intact. But broken small pins? I just can't get there, but I've been wrong before, my Wife can attest to that.

Chad