Clunks when turning and on uneven ground

[Matthew Jeschke]

This is driving me NUTS. I've nearly rebuild my entire truck / is a project vehicle. Including much of the suspension. I developed a clunk. It's intermittent but seems to happen when the suspension is unevenly loaded (uneven surface) and turning. It also seems to come from the driver side.

Here's what I've checked (Inspection Video HERE):
1. ball joints are all good
2. Steering bar is rock solid, including tie rods
3. Sway bar - ends were a bit loose so tightened them back up. Bushings to frame are old but no metal to metal contact. Play checked side to side and up and down on both control arms... none present.
4. Engine appears to be held perfectly in place / no exhaust rubbing or any of that. I also have new motor mounts.
5. Intermediate steering shaft is solid... no slop. Maybe dry? Inspection HERE
6. Shock isolators are crooked so I took one apart, nowhere is the shaft hitting the mount. It's DEAD in the center. Inspection HERE

Out of additional ideas or things to check, or even how to further diagnose this. It's driving me nuts.

 

[2012 Yukon XL]

Maybe this is the answer to your problem.

Technical Service Bulletin
#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.
Diagnosis

1. If the vehicle is equipped with aftermarket (non-GM Accessory) running boards or the running board is mounted using the body mount bolt, remove the running boards prior to test driving the vehicle. This will eliminate the running boards as the possible cause of the noise.
2. Install the J-39570 Chassis Ears to the frame rail at or near the body mounts.
3. Test drive the vehicle to identify which mount is suspect.

Correction

Install an insulator at the suspect mount(s). The insulator should be installed between the upper portion of the body mount and the frame bracket. The #1 mount is the mount located just under the A-pillar. The #2 mount is the mount located just under the B-pillar. The #3 mount is the mount located just under the C-pillar. Use the procedure listed below.

INSULATOR PART NUMBER 15899719

1. Raise the vehicle on the hoist. It is recommended to use a four-post lift or strap the vehicle frame to the hoist arms.
2. For the left side mounts only, remove the intermediate park brake cable. Perform the following steps:
2.1. Remove the nut from the park brake equalizer.
2.2. Remove the intermediate cable from the equalizer.
2.3. Depress the retaining tabs that secure the park brake cable to the frame.
2.4. Pull slightly on the cable from the mounting area in order to provide slack for body movement without binding the cable.
3. Remove all of the body mount bolts on the side being repaired.
4. Properly support the body at the body mount area.
Caution: When you remove the body mount, do NOT separate the frame from the body more than is necessary. Possible personal injury and damage to multiple parts may result.
5. Lower the chassis accordingly in order to remove the upper portion of the body mount.
6. Install the new insulator to the bottom of the top portion of the body mount. The picture shows the insulator (1) location after the body mount is reassembled.
7. Install the body mount to the frame bracket.
8. Perform the following procedure before installing the bolts.
8.1. Clean the bolt threads of all the original thread locking compound.
8.2. Clean the threads of the bolt with denatured alcohol or equivalent and allow to dry.
8.3. Apply Threadlocker, GM P/N 89021297 (In Canada, use P/N 10953488).
9. Install the body mount bolts.

Tighten
For 2003, 2004 and 2005 model year, tighten the bolts to 85 N·m (63 lb ft).

Tighten
For 2006-2008 model year, tighten the bolts to 100 N·m (74 lb ft).
10. Reinstall the intermediate park brake cable (left side only).

The part looks like a giant nylon fender washer. I hope it helps.

 

[BigE]

Make sure to check your torsion bar crossmember bushings as well.

 

[Matthew Jeschke]

Thanks for pointers! My email went down and I wasn't able to get the notifications until now. I may have found it!

I was so annoyed I took the tire off AGAIN for the millionth time. I was going to see if maybe my axle was loose. I first pulled hard in and out on the tie rod. And low and behold I have a VERY MINUTE amount of play in the tie rod. There is definitely play though.

I'm super amazed though. Long story but ALL the factory ball joints survived w/o issue except this one. Really amazed by that. They've gotten very good at making these things, especially considering much of this vehicles life was off road.

I will do both sides & both ends despite only inner driver side is bad. I'll save the extra good / complete tierod for a spare offroad. I bought these new brand MovTech off RockAuto, with Moog inners. This movetech is made in Canada and wanted to give it a try. It seems to be highly recommended. I'm starting to have troubles with Moog. I think they make some of their stuff in China now?

 

[Matthew Jeschke]

I believe the problem is solved Have to go for a spin on some forest service roads to see for sure.

 

[Matthew Jeschke]

Mission accomplished no more clunks Tie rods don't look half bad either!

 

[corvette744]

Thanks for pointers! My email went down and I wasn't able to get the notifications until now. I may have found it!

I was so annoyed I took the tire off AGAIN for the millionth time. I was going to see if maybe my axle was loose. I first pulled hard in and out on the tie rod. And low and behold I have a VERY MINUTE amount of play in the tie rod. There is definitely play though.

I'm super amazed though. Long story but ALL the factory ball joints survived w/o issue except this one. Really amazed by that. They've gotten very good at making these things, especially considering much of this vehicles life was off road.

I will do both sides & both ends despite only inner driver side is bad. I'll save the extra good / complete tierod for a spare offroad. I bought these new brand MovTech off RockAuto, with Moog inners. This movetech is made in Canada and wanted to give it a try. It seems to be highly recommended. I'm starting to have troubles with Moog. I think they make some of their stuff in China now?

Whats the part numbers for the inner and outer that you used.

 

[OR VietVet]

Glad it is fixed. My guess was going to be something at the steering gear mount on the frame or crack at the mount area on the frame.

 

[Matthew Jeschke]

Whats the part numbers for the inner and outer that you used.

Sorry, for late reply. For some reason I'm not getting email notifications from the forum anymore.

Moog ES3488
MOVETECH TXES3493T

FYI ~ If I had it to do over I'd I'd just buy the Rare Parts HD Tie Rod Assembly. They're $70 more at most than doing the sleeves once you buy all new rods, ends, etc.

H.D. TIE ROD ASSEMBLY

Sold in PairsReplaces Undersize OE assembly 1.000 Diameter Outer Forging eliminates buckling point. Steel on Steel Greasable inner and Outer First to market proven design.WARRANTY INFORMATION AVAILABLE AT RAREPARTS.COM/WARRANTY

shop.rareparts.com

 

[tRidiot]

Sorry, for late reply. For some reason I'm not getting email notifications from the forum anymore.

Moog ES3488
MOVETECH TXES3493T

FYI ~ If I had it to do over I'd I'd just buy the Rare Parts HD Tie Rod Assembly. They're $70 more at most than doing the sleeves once you buy all new rods, ends, etc.

H.D. TIE ROD ASSEMBLY

Sold in PairsReplaces Undersize OE assembly 1.000 Diameter Outer Forging eliminates buckling point. Steel on Steel Greasable inner and Outer First to market proven design.WARRANTY INFORMATION AVAILABLE AT RAREPARTS.COM/WARRANTY

shop.rareparts.com

I'm gonna correct this, as you've been typing MOVETECH and it doesn't come up in searching the forum as I had been doing. When looking for reviews on MEVOTECH stuff. Maybe this will bring some people here to this thread if they search MEVOTECH, I found one about their control arms/ball joints when I was looking and they did very poorly for someone here.

Once again, just correcting for MEVOTECH not MOVETECH simply for search purposes for others.

 

[Matthew Jeschke]

Good catch! Mevotech, I got the name mixed up.

So the plot thickens! I don't think I posted my next round of parts darts. Bleeping thing kept clunking! So I said the he LL with it and COMPLETELY tore it down...

All new Energy Suspension front upper and lower control arm bushings.
All new Mevotech upper and lower control arm ball joints
New front bump stops

Ug. It still clunks. I cannot for the LIFE of me figure out what's clunking. It seems to happen when I'm off road and articulating the suspension.

I have Bilstein 5100 shocks all round with about 20,000 miles on them. Boots are DESTROYED... Not sure if they can get dirty and make some noise when exercised.

I'm thinking of replacing the sway bar bushings (they look fine but are original 250k miles). The only thing I can think of after that I've not replaced is the steering shaft... but if fiddle with it and cannot find any play in the line.

My rear bushings are SHOT... But no slop in any of them, nothing that would create a clunk. I should really redo those as well but not really eager to jump into that just yet.

Any ideas?

 

[wjburken]

Good catch! Mevotech, I got the name mixed up.

So the plot thickens! I don't think I posted my next round of parts darts. Bleeping thing kept clunking! So I said the he LL with it and COMPLETELY tore it down...

All new Energy Suspension front upper and lower control arm bushings.
All new Mevotech upper and lower control arm ball joints
New front bump stops

Ug. It still clunks. I cannot for the LIFE of me figure out what's clunking. It seems to happen when I'm off road and articulating the suspension.

I have Bilstein 5100 shocks all round with about 20,000 miles on them. Boots are DESTROYED... Not sure if they can get dirty and make some noise when exercised.

I'm thinking of replacing the sway bar bushings (they look fine but are original 250k miles). The only thing I can think of after that I've not replaced is the steering shaft... but if fiddle with it and cannot find any play in the line.

My rear bushings are SHOT... But no slop in any of them, nothing that would create a clunk. I should really redo those as well but not really eager to jump into that just yet.

Any ideas?

Is the clunk audible or are you just feeling it?

Silly question,but you’ve checked all the stuff like the jack and stuff to make everything is locked down tight, right?

How much play do you have in your rear axles?

 

[tRidiot]

Sway bar bushings should be pretty easy to replace, right? I mean, compared to what all you've done so far. But then, I don't know that I'd expect them to make clunking noises.

 

[mpope2]

Have you checked the CV shaft on that side?

 

[Donal]

Good catch! Mevotech, I got the name mixed up.

So the plot thickens! I don't think I posted my next round of parts darts. Bleeping thing kept clunking! So I said the he LL with it and COMPLETELY tore it down...

All new Energy Suspension front upper and lower control arm bushings.
All new Mevotech upper and lower control arm ball joints
New front bump stops

Ug. It still clunks. I cannot for the LIFE of me figure out what's clunking. It seems to happen when I'm off road and articulating the suspension.

I have Bilstein 5100 shocks all round with about 20,000 miles on them. Boots are DESTROYED... Not sure if they can get dirty and make some noise when exercised.

I'm thinking of replacing the sway bar bushings (they look fine but are original 250k miles). The only thing I can think of after that I've not replaced is the steering shaft... but if fiddle with it and cannot find any play in the line.

My rear bushings are SHOT... But no slop in any of them, nothing that would create a clunk. I should really redo those as well but not really eager to jump into that just yet.

Any ideas?

Take a look at the torsion bar hex and socket fit in the control arm. If you can see a space between the hex and socket, fashion thin wood wedges and drive into the spaces. Test drive over the uneven terrain and determine if any improvement.

 

[Matthew Jeschke]

I feel so bad for some reason I never get my notifications from the forum anymore. All very great suggestions! I have not tried them.

@wjburken it is audible. Not sure if I can feel in steering as I have quite a bit of slop in steering, another post on that linked below. I kind of suspect pitman arm / steering bar linkage.

Rebuilding a steering box

Went to have a my 2001 Z71 Tahoe aligned. One of the FEW places I've not rebuild is the steering box. There's ZERO play in front suspension / steering joints. However, the steering wheel seems a little spongy. I kind of thought was normal performance as it doesn't clunk or anything. However, I...

www.tahoeyukonforum.com

I installed a new to my truck rear end. Before putting it in I pulled cover off and checked gear lash. All I remember is it was well within factory spec. However, reverse to drive I do feel slop which is a different question I hope to answer some day (transfer case wear?).

@tRidiot for sure. Biggest problem is finding time in my schedule when I am buy the parts store to get the sway bar bushings. I'm 100% going polly, I LOVE LOVE LOVE the energy suspension stuff. The bad press is all wrong on them. They have pliability and only ride BETTER than stock. I think people are fixing wrong thing or installing them with wrong grease (squeek).

@mpope2 yes and no. Good reminder. Years ago I thought my CV shafts were bad so I bought a new (used) set from junkyard after cherry picking the lot. Turns out my issue was a loose door haha. I've since removed the axel nut w/ dust cover. I marked end of bolt and nut. Hasn't moved from when I torqued it on. However, I need to see if there's slop in the shaft / knuckles / bendy parts. They show no signs of leaking.

@Donal BEAUTIFUL, this maybe my problem. I always wondered as I DO see light / gap there between torsion bar the control arm. Is that typical or result of wear? I always wondered if that was an issue / could create noise. I will drive some wood wedges in there and see if it helps! Great suggestion!

 

[Donal]

The joint of the torsion bar and arm has to be loose because the bar travels in an arc around the pivot point of the lower arm as the suspension works. The popsicle stick trick just assists in locating the noise source. the sticks will soon be purged as the bar functions. The torsion bar is joined to the arm about 3 inches from the pivot point of the lower arm and moves in arc of the 3 inch radius as the suspension travels. So each torsion bar sees a radial load and would see a bending load if the joint was a tight fitting joint. The cross member that the rear end of the torsion fits in also has rubber bushing to check and replace if need. Think of the torsion bars load as being the algebraic sum of the total load supported. This means that one bar may be loaded higher than the other side. In situation where the road surface is rough, pitted or like notification cuts along the edge of the pavement, each side of the vehicle's suspension will see different loads. Each shock asborber, torsion bar, etc. All try to stabilize the vehicle. If one torsion bar has a light preload, compared to the other side, the loose fitting joint may be generating the noise.
The Z dimension should be the same for both sides and should be corrected as the first step in trouble shooting front suspensions. The Z height is illustrated in Chapter 10 of the manual recently made available to members.

 

[Matthew Jeschke]

How do you measure your z height? I used a level and tape measure. Not exactly high precision... Curious if there is a better method. I'll go through your routine to troubleshoot. Thanks!

 

[Matthew Jeschke]

Well, a side effect of all this is my steering and handling is MUCH improved! Poly bushings ALL the way The energy suspension sway bar bushings and end links REALLY livened up the front in. It's AMAZING.