Bulletin No.: 15-NA-082
Date: Dec-2015

Subject:

Clunking Noise from Front of Vehicle During Turns and/or Bumps

Attention:

This Bulletin also applies to any of the models that may be Export vehicles.

Brand:

Model:

Model Year:

VIN:

from

to

from

Engine:

Transmission:

to

Cadillac

Escalade EXT

2007

2013

All

All

Cadillac

Escalade,
Escalade ESV

2007

2016

All

All

Chevrolet

Avalanche

2007

2013

All

All

Chevrolet

Silverado 1500,
Suburban 1500,
Tahoe

2007

2016

All

All

GMC

Sierra 1500,
Yukon, Yukon
XL 1500

2007

2016

All

All

Condition

Some customers may comment on a clunking noise originating from the front of the vehicle that is more
predominant during turns or traveling over bumps.

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Cause

This may be caused by a damaged stabilizer shaft frame bracket. There have been some cases in which
the bracket is cracked, as shown. This condition has been found to be the result of insufficient welds
between the bracket and frame rail. There have been some cases on older vehicles of corrosion affecting
the bracket.

Correction
If you encounter a vehicle with the above concern, follow the procedure below to install a new stabilizer shaft bracket to the frame.
1.

Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.

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2.

Raise the vehicle in the air and inspect the stabilizer shaft frame brackets (both left and right) for any abnormalities or cracks and inspect welds to
ensure good alignment and integrity. Refer to Lifting and Jacking the Vehicle in SI.
Note: Be sure to inspect frame rails for any cracks or damage in relation to the stabilizer bracket. If the frame rail itself is cracked or damaged, repair
should not be attempted.

3.

Once verified that the bracket is damaged or the welds are insufficient, remove the stabilizer shaft. Refer to Stabilizer Shaft Replacement in SI.

4.

On 4WD models, once the stabilizer shaft is removed also remove the front frame/front axle mount exhaust heat shield (1) located above the stabilizer
bracket.

5.

With the stabilizer shaft and shield removed, using a rag and wax/grease removing solvent, remove the wax coating and any grease, oil, or
undercoating from the truck frame in the affected repair area.
Important: Be sure to remove all wax coating around the areas of the bracket. If the wax coating is not fully removed, this could affect the weld quality
when installing the new bracket.

6.

After all the wax coating is removed, using a cut off wheel, remove the old bracket from the frame.

Warning: To avoid personal injury when exposed to welding flashes or to galvanized (Zinc Oxide) metal toxic fumes while
grinding/cutting on any type of metal or sheet molded compound, you must work in a properly ventilated area, wearing an approved
respirator, eye protection , earplugs, welding gloves, and protective clothing.
Important: Be sure to not cut the frame in process of removing the bracket.

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7.

After the bracket has been removed, using an angle grinder with 24 grit sand paper or equivalent clean the areas of any excess bracket weld material
from the frame so that the new bracket can sit flush in the location of the old one.
Important: Be sure to not grind away any frame material, only remove the weld material.

8.

Clean the area of all debris in preparation of the new bracket to be welded to the frame.
Important: Be sure to inspect frame rails for any cracks or damage in relation to the stabilizer bracket. If the frame rail itself is cracked or damaged,
repair should not be attempted.

9.

After the area is clean of all debris, place the new bracket in the location of the removed one. The bracket should seat against the frame crossmember
bracket in the most forward position, along the lower surface of the frame rail, and along the inner surface of the frame rail in the rear.
Note: The new bracket will need the welding locations stripped of all coating. Be sure to grind all edges of the new bracket so that the quality of the weld
will not be affected.

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10. After the bracket is in location, tack weld the bracket to the frame in all 4 corners of the bracket. This will keep the bracket from moving while welding
the bracket fully to the frame.

11. After the bracket is tack welded in the location, loosely position the stabilizer shaft to verify that the bracket is in the correct location. Refer to Stabilizer
Shaft Replacement in SI.
12. After verifying that the bracket is in the correct location, remove the stabilizer shaft. Refer to Stabilizer Shaft Replacement in SI.

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13. Continuous-weld the new bracket into position. Ensure the rear vertical weld (1) is extended approximately 15 mm above the edge of the bracket.
Note: When welding, be sure to start from the bottom of the bracket and work your way upward.
Note: Gas metal arc weld using ER70S-3 electrode and an Argon CO2 protective gas mixture. Alternatively, meeting AWS 7013.
Note: Provide a continuous weld around the bracket. If access does not permit a continuous weld, make a 6 mm minimum overlap of adjacent welds.
Warning: To avoid personal injury when exposed to welding flashes or to galvanized (Zinc Oxide) metal toxic fumes while
grinding/cutting on any type of metal or sheet molded compound, you must work in a properly ventilated area, wearing an approved
respirator, eye protection , earplugs, welding gloves, and protective clothing.
14. After the bracket has been fully welded to the frame, using Lloyd’s Pure Prep™ Metal Surface Preparation P/N 25418 (10 fluid ounce bottle), or
equivalent, saturate a towel or Scotch-Brite™ (3M) pad with the pre-diluted solution and scrub the area well, rendering a foaming of the Pure Prep.™
This will greatly improve adhesion and corrosion resistance in the repair areas.
15. Using a water dampened clean towel, remove any residue and dry the affected area. Dry the repair area completely using an air hose to blow dry the
frame and bracket.
16. Check the repair area for phosphate treatment by wiping it to see if any corrosion residue can be picked up. Correctly treated areas will not have any
residue on the surface.

17. Apply a light flash-coat of Lloyds Kryptonite Metal Treatment P/N 36502 Life Long Rust Protection (14 ounce aerosol), or equivalent, to all bare areas of
the frame where the wax coating was removed. This first coat should flash in approximately 3-5 minutes. Apply a light flash-coat to the inside of the
frame rail using existing access holes, as shown. Insert the straw of the aerosol can as far as possible, and slowly work the straw back out while
applying material.

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18. Apply a second coat of Lloyds Kryptonite. This can be a heavy coat; double and triple passes with this product, over a light first coat, are not a problem.

19. We suggest top coating the Lloyds Kryptonite with Daubert Nox-Rust® P/N X-121B “One Coat Rust Preventative Coating” (aerosol), or equivalent.
20. Reinstall the stabilizer shaft with new stabilizer shaft clamp bolts. With new stabilizer thread cutting bolts, drive the bolts to cut the new threads, then
loosen the bolts two turns and then torque to 50 Y (37 lb ft). Refer to Stabilizer Shaft Replacement in SI.
Note: The stabilizer shaft clamp bolt attachment holes on the new bracket are not threaded, the clamp bolts are thread cutting.
21. On 4WD models, install the front frame/front axle mount exhaust heat shield.
22. Reconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection.

Parts Information
Dealers should obtain 25418 and 36502 by contacting Lloyds by e-mail at [email protected], or by calling 1-800-361-6766.
U.S. Dealers can obtain the X-121B topcoat by contacting the Daubert website at www.daubertchemical.com or inside the U.S. only, by calling 1-800-914-0034.
Canadian dealers must contact the Daubert distributor in Canada, Corrosion Control Coatings Ltd, by faxing the form below to 1-800-563-8078.
Part Number

Description

84037074

Bracket – Drivetrain & Frt Susp Frm Stab (Left Hand)

84037075

Bracket – Drivetrain & Frt Susp Frm Stab (Right Hand)

11570934 (2 Qty)

SCREW-HEX FLANGE HEAD TAPPING

Warranty Information
For vehicles repaired under the Bumper-to-Bumper coverage (Canada Base Warranty coverage), use the following labor operation. Reference the Applicable
Warranties section of Investigate Vehicle History (IVH) for coverage information.
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Labor Operation

Description

Labor Time

1480628*

Repair and Replace Stabilizer Bracket on One Side

2.5 hrs

Add

Replace Both Stabilizer Brackets

1.5 hrs

*This is a unique Labor Operation for Bulletin use only.
Additional Keywords: Sway

Version

2

Modified

December 16, 2015 – Updated Important statements and added Additional Keywords.

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GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may
occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,
safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that
your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
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