by Bob Beranek
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I’m sure that many of you have noticed that there has been a higher number of noise complaints recently. Have you ever wondered why? The answer is exposed edge glass mounting. Since the popularity of exposed edge glass mounting came into being with the Saint Gobain’s Pre-Applied Adhesive System (PAAS), many other vehicle manufacturers have noticed the benefits of its design.

  • There are fewer parts to design and manufacturer;
  • Less labor costs to install the finishing moldings;
  • Without an over-glass molding there is less drag and better fuel economy; and
  • More aesthetically appealing.

There are also some pros and cons for the auto glass technician as well.

Pros

  • No moldings to take off so installation times are reduced;
  • No clips to be broken and replaced so costs are reduced.

Cons

  • Removal damage easily visible;
  • Bead application must be precise or cleanup is a problem;
  • Noise complaints increase.

Today, I want to address the noise complaint issue. Have you ever had a customer complain, “That ever since the glass was replaced, there is a noise they’ve never heard before?” I think we all have. The fact is that the noise is not new, it is just different.

All vehicles have noises manufactured in them the day we drive it off the lot. If the noise is such that we cannot tolerate them, we don’t buy the vehicle. However, if the sounds are minor, or don’t irritate us particularly, we will buy the vehicle and live with the noise. Eventually, we don’t hear it anymore because we get used to it, and, in our minds, it ceases to exist.

Then comes Otto’s Glass to replace the windshield and the gap between the exposed edge of the glass, and the wall of the pinchweld is slightly different than before. If it is a smaller gap, there is a higher pitched “whistle.” If it is a larger gap, there is an “air rush” sound. Either way, the sound is different not new. There is no such thing as zero sound.

Air has to go somewhere when it comes in contact with the vehicle. If it is forced between the glass and the body gap, the rush of air will create a noise. How that noise is heard depends on where it enters the gap, travels through the length of the gap and how it escapes. The only way to stop the noise complaint is to disrupt the air flow thus stopping the air from creating a rush or whistle.

Here are some actions you can take to reduce the noise complaints:

  • Add a moulding – Yes, it will change the look, but does the customer want a quiet ride or stylish looks? Sometimes you can’t have both. If you are a good salesman, you can sell them on a “J” moulding which will most definitely remove the noise issue, but it will also be the most noticeable to the customer. Or, you could suggest or install an underside moulding which will be far less noticeable but is not as fail safe as the addition of a “J” moulding. The underside moulding will divert the air causing the noise.
  • Measure and replicate the size of the gap – Use a shim or measuring device to note the size of the gap between the glass edge and the wall of the pinchweld. Then exactly replicate the gap upon setting the glass into the opening. Adjust where needed.
  • Disrupt the air flow by adding a strategic ball of adhesive – If the vehicle has “A” pillar moldings but has an exposed edge top, you should place a small ball of butyl tape or dollop of urethane under the side moldings and between the glass edge and the pinchweld wall. This will disrupt the flow of the air and eliminate air rush or an upper corner wind whistle.
  • Make sure the glass surface is slightly below the flush-point of the roof line – It is a little known fact that the glass should be slightly inset into the opening for exposed edge glass. This directive came from BMW many years ago for their vehicles. BMW even had a tool that looked like the shape of the state of Nebraska to measure the indentation. That tool should not be used to measure all vehicles because all vehicles have different roof configurations, but the glass should be slightly indented into the opening and not be flush to the roof line.

I hope these tips and ideas will help with your reduction of noise complaints. Just remember that the noise they hear is not new, just different.

We owe a thank you to John McGee, Kim Speer and Bob Farrell from Binswanger Glass for a heads up on the new 2013 Cadillac SRX Four-Door Utility. NAGS lists two windshields for the model, the DW01816 with solar and upper molding and the DW01817 with solar, molding and rain sensor bracket. Kim discovered that there was another option for that model which is a windshield with a lane departure system. Once Kim ordered the glass from the dealer she discovered that the dealer glass has a special window to the passenger side of the mirror/sensor bracket. This window allows the camera for the lane departure system to see the road.

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It looks like the glass has four mounting tabs attached to the glass where the camera is secured. The camera is removed for installation but Cadillac is clear that recalibration is not necessary when the windshield is replaced.  The following are instructions given by Cadillac for replacement and re-installation.

The calibration process for the front view camera system is necessary when a front view camera module is replaced by a new one. This process shall not be required when only replacing the windshield and the front view camera module has been mounted again properly. This process shall be completed within 3–5 minutes when the correct driving conditions are met. If conditions are not met correct, the front view camera module shall continuously run the service point calibration until successfully completed. This process shall work across ignition cycles and shall not be required to be re-initialized at start up. If the Lane Departure Warning Switch is pressed during calibration, the indictor will flash momentarily and then stay out — this is normal operation.

The calibration procedure will start automatically after SPS programming is complete. During this time the Lane Departure Warning amber indicator will illuminate.

To calibrate the front camera, operate the vehicle in the following conditions until the calibration is complete:

  • Clean windshield.
  • Avoid lane changes.
  • Maintain vehicle speeds between 56-90 km/h (35-56 MPH).
  • Ensure the road contains visible references (well-defined lane markings, curbs, etc.).

Once the procedure is complete, the amber indicator will turn off. Shortly after the green ready to assist light should turn on as long as all conditions are met for normal operation. The system is then ready to assist.

One or more of the following conditions may increase the length of time required to complete the self-calibration procedure:

  • Heavy traffic
  • Stop and go traffic
  • Mountain roads
  • Curves in roadway
  • Poor contrast lane markings
  • Botts’ Dots type lane markings
  • Operating the vehicle speed is greater than 90 km/h (56 MPH)
  • Driving through snow or fog, or driving directly into the sun
  • Camera not properly installed. Verify it is snapped into tabs and is secure.

Conditions that will prevent completion of the self-calibration procedure:

  • Dirty windshield glass or obstruction on windshield
  • Operating the vehicle with speed less than 56 km/h (35 MPH)
  • No visible lane markings
  • Severe weather where lane markings cannot be seen
  • Camera not properly installed. Verify it is snapped into tabs and is secure.

NAGS has been notified about the discrepancy in the numbers in this model and they will make adjustments to their catalogues and database. The instructions by Cadillac should be all you need to replace this glass successfully.