by Bob Beranek
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I read a thread on glassBYTEs.com™ the other week titled “2014 Hyundai Sonata Stress Cracks,” and a couple of things came to mind. Some of you know that my son Jay works for a large dealership group here in Madison, Wis. One of the makes his dealership sells is Hyundai. This past week Jay told me that he has personally witnessed a number of 2012, 2013 and 2014 Hyundai vehicles with stress cracks in the windshields. Although Jay had a couple of thoughts on the cause of the breaks, I needed to see it myself before making a diagnosis.

Another thing he said piqued my interest. He said that the new Hyundai windshields were more difficult to install now due to the thinness of the urethane bead between the glass and the pinchweld. He said the thin bead makes the glass more difficult to cut out. According to Jay, it is hard to get a cold knife blade under the glass, and the glass breaks up easily during removal. Interesting.

A unibody vehicle is one that has a great deal of body movement as it travels a roadway. It ebbs and flows with the roadway, twisting and turning in all directions. All of the body panels must be manufactured to take this movement into consideration. The sheet metal of the body has a certain amount of flexibility in its movement but the glass panels are less flexible. To account for the movement of the body in relation to the stationary glass parts, the engineers use the urethane adhesive to cushion and allow the movement of the glass in the opening. If the urethane bead is thin or too stiff, the glass will not move sufficiently and may stress break. Could this be the reason for an increase of stress breaks in the Hyundai?

Another observation made is that at Jay’s dealership they used to buy aftermarket glass for Hyundai replacements, but they found that aftermarket glass was frequently out-of-bend, so they went back to using OEM glass. If the aftermarket glass is slightly out-of-bend, then patting or spanking the glass to seal it could cause a break during installation. In addition, glass that is out-of-bend will give when patting it into place, but it will then spring back, causing the urethane to string out. This may cause leaks or bonding issues. It is always better to smooth out the glass to seal rather than patting or spanking it into place.

Comments (7)

  1. […] TODAY’S BLOG: Hyundai Stress Cracks […]

    • Mark Hillegass said on 21-12-2016

      Bob,

      Could you or your son send me some information of your discoveries regarding the windshields randomly cracking due to stress? I had that happen two weeks ago while my car was parked under covered parking. I went to get into my car to head to work and saw the glass. The glass doesn’t have any marks, dents, or anything on the outside or inside. It’s completely smooth. I’m having to take Hyundai to arbitration over the windshield because they said it’s not defective when it is. It cracked right by the radio antenna. Ironically, a Hyundai rep said windshields are cracking on other vehicles, but hasn’t happened on the Sonatas yet. I have a 2014 Sonata. Also, does your son know anything about the Sonatas shaking, reeving, and trying to accelerate while the brake is being applied in traffic? That’s the ultimate reason Hyundai and I are going to court. I’ve had small acceleration misfires that have now turned into that twice. Hyundai always says that haven’t seen this problem yet nor can duplicate it. Any help would greatly be appreciated!

  2. John R. Allen said on 21-05-2015

    GREAT observations! I think this could also be the issue with the panoramic sunroofs that are all “exploding”. Look at the bead of urethane from the metal frame to the glass. In some cases the glass is practically touching the frame. Glass gets hot expands, or cold and contracts and you hit a pot hole…Could be happening that way. Some manufacturers use a high bead such as the Honda Odyssey and CRV’s….I have not seen any issues with them. Just my thoughts…..

  3. Frank Thomas said on 22-05-2015

    Have had a couple of stress cracks during the last few years, thanks for the up-date. I assumed it was tech error but you know what happens when we assume.
    Thanks Bob

  4. Larry said on 25-05-2015

    I have no problems cutting these out we do a ton of them for a rental company, have yet to see a stress crack. As far as them breaking up when coming out, not have had that issue either, if i see a tee tiny bead i use my wire…

  5. Donald Morgan said on 23-03-2018

    I have a 2015 Hyundai Santa Fe. This morning when I went out to leave there is a small crack that’s developed on the drivers side. I did not get not get hit by anything and upon further inspection I see nothing but the crack! I’m going to see what the dealer says.

  6. Maureen said on 08-02-2019

    2015 Santa fe…woke up to 4″ smooth crack on driver’s side…& it shimmies a lot…just got it 2 mos ago,ins & warranty,covered do you think?

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