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02 Z71 Suspension Clunk Help Please

chartersj

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chartersj Enthusiast

chartersj

Posted
Posted

hello

i have a 2002 silverado ext cab lt z71 with 220,000kms, my truck has developed a clunking noise coming from the rear of the truck, this is not the common slip-yoke clunk, because i had that too. It clunks when going over any quick bumps, and sometimes over the slow long bumps that makes the suspension travel more. I can also make it do it when i jump on the back bumper, and then it seems to be coming more from the drivers side of the truck. The truck has the same leaf springs and shocks in the rear since it had 70,000kms and not sure if either were changed before that but i am thinking probably not. I have had it to the garage and cannot find anything, and i have seached many forums online and cannot find anything other than people with slip-yoke clunks. Has anyone had these same symptoms?? thanks alot.

jdewolfe Enthusiast

jdewolfe

Posted
Posted

I have had a noise like that before when I had an old 91 S-10. Turns out I snapped a leaf spring. Couldn't tell though until I jacked up the rear end and took the weight of the truck off. Just an idea...

 

Jeff

mmardesich New Member

mmardesich

Posted
Posted

Don't know if this applies to your truck, but this is what I'm trying for the same symtoms.

 

#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).

 

This post has been edited by sk1er18: Apr 29 2009, 03:25 PM

 

 

Attached thumbnail(s) img-resized.png Reduced 64%post-14076-1241043787_thumb.png 677 x 610 (7.11K)//

 

img-resized.png Reduced 51%post-14076-1241043798_thumb.png 503 x 377 (77.03K)//

Grendelkndl New Member

Grendelkndl

Posted
Posted

I had a similar problem with my Truck. I took it back to the dealer several times and they replaced the body mount once and that didn't fix it, and then replaced the slip-yolk and that didn't fix it either. Finally, one day in my drive way i figured out that it was coming from the rear leaf springs so i got my floor jack out and jacked up the rear of the truck by the receiver hitch until the tires were just about to come off the ground and i sprayed lithium grease in between all the leaves and the Clucking noise went away. Maybe you are having a similar problem with your springs...

chartersj Enthusiast

chartersj

Posted
  • Author
Posted

thanks for all the replies. I have noticed a gap between the leaf springs, but have not noticed any cracks where a leaf could be broken, you should be able to see a crack if one was broken wouldnt you? I will try and jack it up to see, and spray some grease in between them, im thinking thats were i should start. If not that im thinking change the shocks...after 220000kms they could probably stand to be changed. I will take a look at all your opinions though, very much appreciated

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