Technical Service Bulletins

Dealing with a Caddy clunk

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Dealing with a Caddy clunk

Some owners of 2004-2012 Cadillac Escalade vehicles may comment on a pop or clunk type noise while turning or driving on uneven road surfaces. The noise can be heard and/or felt at either the driver’s or front passenger floor pan areas. Under certain conditions, normal movement between the frame and the #1, #2 or #3 body mounts may cause this noise to occur.

This also applies to 2004-2012 Chevrolet Avalanche, Silverado, Suburban and Tahoe vehicles, and GMC Sierra, Denali and Yukon vehicles.

If the vehicle is equipped with aftermarket (non-GM) running boards or if 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.

Install the J-39570 Chassis Ears to the frame rail at or near the body mounts. Test drive the vehicle to identify which mount is suspect.


In order to correct the issue, install an insulator at the suspect mount(s). The body mount insulator is available as GM P/N 15899719.

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 located just under the B-pillar. The #3 mount is located just under the C-pillar.

Raise the vehicle on a hoist. It is recommended to use a four-post lift, or strap the vehicle frame to the hoist arms.

For the left side mounts only, remove the intermediate park brake cable. Perform the following steps:

1. Remove the nut from the park brake equalizer.

2. Remove the intermediate cable from the equalizer.

3. Depress the retaining tabs that secure the park brake cable to the frame.

4. Pull slightly on the cable from the mounting area in order to provide slack for body movement without binding the cable.

5. Remove all of the body mount bolts on the side being repaired. 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.

6. Lower the chassis accordingly in order to remove the upper portion of the body mount.

7. Install the new insulator to the bottom of the top portion of the body mount.

8. Install the body mount to the frame bracket.

9. Perform the following steps before installing the bolts:

* Clean the bolt threads of all original thread locking compound.

* Clean the threads of the bolts with denatured alcohol and allow to dry.

* Apply Threadlocker, GM P/N 89021297 to bolt threads.

 Install the body mount bolts. For 2003, 2004 and 2005 model years, tighten the bolts to 63 ft.-lbs. For 2006-2012 model years, tighten the bolts to 74 ft.-lbs.

Reinstall the intermediate park brake cable (left side only).

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