Interior - Excessive Wind Noise From Rear Interior
TECHNICALBulletin No.: 10-08-58-001F
Date: December 14, 2011
Subject: Excessive Wind Noise Coming from Rear Interior of Vehicle (Perform Repair as Outlined)
Models:
2007-2012 Chevrolet Silverado
2007-2012 GMC Sierra
Supercede:
This bulletin is being revised to add the 2012 model year and include all cab configurations. Also, information related to the latest generation insulator design was updated and the Further Repair for Customer Enthusiasm section was removed. Please discard Corporate Bulletin Number 10-08-58-001E (Section 08 - Body and Accessories).
Condition
Some customers may comment on hearing excessive wind noise coming from the rear interior of the vehicle.
Cause #1
This condition may be caused by a void in the body filler within the C-pillar.
Cause #2
This condition may be a result of the design of the body rear panel acoustic insulator that is mounted behind the rear seat. The insulator could be one of several early designs (1 or 2 in the above graphic), which demonstrated a lesser success of minimizing wind noise.
Correction #1 - (2007-2010 Model Years Only)
Important
Prior to attempting a repair of the vehicle, it will be necessary to compare it to a like vehicle in similar operating characteristics to determine if it should be considered normal operation or a repairable condition.
1. To properly diagnose the C-pillar body filler issue, complete the following steps:
1. Close the all doors and windows of the vehicle.
2. Without starting the vehicle, turn the vehicle ignition to the ON/RUN position.
3. Press the HVAC selector switch for Outside Air.
4. Turn the HVAC Fan Control to Medium/High.
Note
The air flow that is felt most commonly exits the lower C-pillar opening shown in the graphic above.
5. Run your hand alongside the lower seam of the body at the base of the C-pillar and feel for air flowing out of the bottom of the body.
6. Compare the air flow on the opposite side of the vehicle. If one side exhibits a distinct higher amount of air flow, continue on to the next step in this procedure to start the process of adding sealer to the C-pillar on that side. If no air flow difference is found, skip ahead to Correction #2.
2. To access the inner C-pillar, remove the rear seat and the body lock pillar trim panel. Refer to Body Lock Pillar Trim Replacement (Crew Cab) or Body Lock Pillar Trim Replacement (Extended Cab) in SI.
Figure 1 - Outside View Through C-pillar
Figure 2 - Top View, Section Cut Through C-pillar
3. Inspect the inner baffle/foam within the C-pillar for any voids in the body filler. The examples above show an opening (1) in the baffle at the forward, inboard corner of the right side C-pillar.
4. If a void is found (1), fill it with seam sealer Kent Automotive High-Tech(TM) Clear Sealer, P/N P10200 (5 oz. tube), or equivalent, to eliminate the air flow escape concern.
5. Before reassembly, verify replacement of the proper latest generation body rear panel insulator following the information referenced in Correction #2.
Correction #2 - (2012 and Prior Vehicles, Based on Build Breakpoints in Table)
This repair pertains to the following vehicles:
Note
Vehicles built after the breakpoints noted should have the latest generation body rear panel insulator (shown in graphic above), which is more robust and has the rubber side visible. Verify the vehicle having this latest generation insulator, and if not, order a new service part insulator referencing the parts table below.
Replace the body rear panel insulator, and add additional sound proofing material, following the steps below:
1. Remove the body rear panel insulator. Refer to Body Rear Panel Insulator Replacement (Extended Cab/Crew Cab) in SI.
Note
It has been found that controlling the wind noise at the two pressure relief valve (PRV) locations is the key to quieting the rear cab wind noise. The additional sound proofing steps below have been found to be successful in eliminating most of the objectionable noise.
2. Prior to installing the new insulator service part, complete the following sound proofing steps:
Note
GM P/N 12378195 is not available in Canada. However several equivalents such as *Evercoat (Q-Pads) P/N 100116 and *Dominion Sure Seal (Sound Deadener Pads) BSDE Part 110900 are available through NAPA Auto Parts retailers. Information for finding your local retail location can be obtained online at www.napacanada.com.
- Install noise and vibration sound deadening pads (1) to backside of the body rear panel insulator. Follow the pattern shown above, ensuring they cover the two pressure relief valve (PRV) locations. Use GM P/N 12378195, or equivalents commercially available through *Dynamat(R), Evercoat(R) or Dominion Sure Seal.
Important
Ensure that the shim stock foam pattern does not have any gaps in the corners and that it is securely pressed/attached to the inner rear body panel.
- On both sides of the vehicle, install a double thickness of Kent Automotive Adhesive Back Shim Stock P/N 46515, or equivalent, partially around the two PRV's. Install the foam across the top (1), down the outboard side (2), underneath (3), partially back up the inboard side (4), then finish with a length extending further inboard (5) from the PRV.
Important
Ensure that any C-pillar wiring harnesses/connectors are routed forward of the insulator, and not trapped behind it.
3. Position the body rear panel insulator to the inner rear body panel and install the push pin retainers. Caution should be taken to not disturb the shim stock installed previously.
Important
Ensure that the foam is securely wedged between the outboard edges of the insulator and the wiring harnesses/sheet metal, making sure that any C-pillar wiring harnesses/connectors are routed forward of the insulator and foam, and not trapped behind either of them.
4. Install a length of *Duck Brand Window Air Conditioner Insulating Strip Seal P/N 1284075, or equivalent, down each side C-pillar. Ensure that the foam extends from the top of the insulator to the floor of the vehicle.
Tip
When completing installation of the insulator panel, ensure that the access flap (1) is closed and fully seated into the rest of the insulator material.
5. Complete the installation of the insulator panel and interior trim. Refer to Body Rear Panel Insulator Replacement (Extended Cab/Crew Cab) in SI.
* We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources.
Parts Information
Contact Kent Automotive at 1-888-YES-KENT or online at www.kent-automotive.com.
Duck Brand products, or equivalent, can be obtained from your local hardware or home improvement store.
*GM P/N 12378195 is not available in Canada. However several equivalents such as Evercoat (Q-Pads) P/N 100116 and Dominion Sure Seal (Sound Deadener Pads) BSDE Part 110900 are available through NAPA Auto Parts retailers. Information for finding your local retail location can be obtained online at www.napacanada.com. Dominion Sure Seal (Sound Deadener Pads) BSDE Part 110900 can be obtained by contacting Dominion Sure Seal at 1-800-265-0790.
Warranty Information
For vehicles repaired under warranty, use:
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