Exposed Edge Glass (Part Three)

Have you noticed that noise complaints are up? Customers have been complaining since exposed edge glass came out that air rush or air whistles have occurred after the glass was installed. Is this true or is it another noise they always had, but never heard? I think the answer to that is a little of both.

Jeep, and, in some instances, Chrysler, have been having noise complaints for years and have even issued a Technical Service Bulletin (TSB) on this complaint. TSB 23-030-07 and 23-023-08 are just two, we are aware of, that address howling or wind noise around the windshield area. The main reason for the wind whistle is that the gap between the glass edge and the wall of the pinchweld is too small. The wind rush is caused by the cavernous spaces between and under the glass edge, the urethane bead and the pinchweld wall. To stop the problem it simply needs to disrupt the air flow thus causing the rush to subside and to leave a proper or bigger gap after the glass is installed.

Prevention is worth a pound of cure, so the first thing you must do is question the customer about possible noise leaks before beginning the work. If there is noise reported you may have a legitimate reason to suggest adding a universal moulding to those vehicles that can take one, such as the Jeep Wrangler or Liberty.  If the customer does not report a problem, try selling the fix before the problem occurs by making the customer aware of the problem.

If that doesn’t work, then you will have to use some procedures that will lessen the chance of post-installation problems.

  1. Replicate the gap. Take a measurement of the gap and try to replicate it once the glass is set. Use a tape measure to note the gap size or insert a shim or plastic stick into the gap and mark the depth the stick is inserted. Then use the stick to set the glass properly.
  2. Make the gap wider. Obviously, the wider the gap the less likely it is that it will whistle, but you must make sure that the gap isn’t too wide so that the bond is compromised.  However, by making the gap bigger it can cause the other problem called air rush.
  3. Use an underside moulding. One way to disrupt the air flow and reduce whistling is to apply an underside moulding. It will keep the look similar to OE but it also takes away some of the bonding area. However, if you have plenty of room to add the moulding and replicate the size of the OE bead, it is a great way to prevent the noise problem.
  4. Divert air flow. The older Ford Explorer used a little bead of silicone under the side moulding near the base of the “A” pillar to keep wind whistles from occurring. We can do something similar if the vehicle is equipped with a side moulding and an exposed top edge, such as the Dodge Ram truck. Instead of using silicone, use a small bead of urethane between the glass edge and the wall of the pinchweld.

So, how do we fix the problem after the glass is installed? Anything you can do to disrupt air flow and reduce the overall distance the air will travel, may stop the noise. Some of these fixes may sound drastic, but it may be necessary if the problem was not prevented.

  1. Use an insert moulding. If you can talk the customer into adding a moulding to stop the noise, use an insert (Christmas tree) moulding to bridge the gap and stop the flow.
  2. Add a secondary bead. If you can hide an added bead between the glass edge and pinchweld wall under the “A” pillar moulding, do so in about 5- to 6-inch increments along the pinchweld. If you can’t hide it, try putting a bead below the top of the fender.
  3. Do an R&R. The last resort is to R&R the part and use the methods above in reinstalling the part.

These types of mountings are here to stay, so hone your skills and develop your habits so complaints can be reduced and customer satisfaction can be assured.