by Bob Beranek
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While I wrote this post, my wife Ann was busy making sure that we had everything packed for this week’s trip to Reno, Nev., for the Auto Glass Week™ festivities. When we went to our first national trade show we had no idea the things we were going to learn and see. We knew it was going to be an interesting adventure but we didn’t know the new ideas we were going to discuss and the friends we were going to make.

This year’s event will be no different than the first one we attended. There will be new friends to meet and old friends to share stories and experiences with. There will be new products to explore and new ideas to debate and put to work.

One of the things that I am looking forward to are the seminars and meetings that discuss and decide the future of our industry and how our businesses will have to change to make the most of the new coming trends. Technology is the future and we have to address it, whether we like to or not. I am honored to be part of a panel of experts in a series of seminars addressing, “How Vehicle Technology is Changing Your Business.” Mitch Becker from Abra Auto Body and Glass and Gerry Parij from Saint Gobain-Sekurit join me in presenting the second part of the technology series. The new Advanced Driver Assist Systems and other autonomous systems have been in our industry news for months now and will not go away. So, this series will be very interesting and educational.

Debra Levy from Key communications hit one out of the park in landing one of the most sought-after businessmen in the country, Jack Welch, as a speaker this year. Mr. Welch is one keynote speaker that should not be missed. He alone is worth the price of admission.

Well, I have to make this post short because Ann and I have a lot to do before getting on the plane. We hope to see you there.

Since the introduction of Advanced Driver Assist Systems (ADAS), the need for aftermarket glass replacement companies to use OEM glass has increased substantially. Of course, auto dealers have claimed for years that OEM glass was necessary for the proper operation of the many electronic systems that utilize the glass for mounting or delivery. Is this true?

I got an email recently from a glass shop that installed a top quality windshield in a Cadillac Escalade with the Cadillac Intelligent Collision Avoidance System. It was installed more than six months ago with absolutely no problems with any of the ADAS system components. As a matter of fact, the customer used all of the system components during several road trips. However, recently the cruise control stopped working. None of the other systems malfunctioned but the cruise control didn’t work at all. The customer took the vehicle to the dealer, where another glass company came in and claimed that the malfunction was caused because the original aftermarket replacement shop didn’t use an OEM windshield.

This troubled me. In my experience, the cruise control malfunction could not possibly be caused by the glass if everything worked for six months prior. The features on the Cadillac glass are interconnected to the other components of the system and if one does not work, the others will not work either. Most concerning is that the statement, “the glass wasn’t OEM glass.” It came from another glass company and not from the dealer who may have had an incentive to sell his own glass.

So, what are we to believe?

I hope our readers can help me find out. I have had reports of ADAS that could not be calibrated unless an OEM glass was used. I have heard that aftermarket Chinese parts worked well with some systems and not others. I have heard that curvature, color intensity and thickness all play a part in proper operation. I have always depended on information I glean from my friends in the glass manufacturing industry, coupled with reports I get from trusted technicians and colleagues from the field. I then test things out with personal experience. However, the questions of ADAS and aftermarket glass replacement are too numerous (and growing) for this method of research.

There are many different ADAS systems out there and all are systems that work well. However, some are more sophisticated than others and some require more exact specifications from other supporting equipment. If you have read my past postings then you know that there has been a wide range of reports and facts. Honda requires OEM glass for proper ADAS operation. All ADAS equipped vehicles require re-calibration. And ADAS in Cadillacs and other GM vehicles require no re-calibration. All these past postings are correct in their content but none of them have given us a definitive answer to all our questions.

So, I am sending out a request to technicians, manufacturers of glass and vehicles, technology gurus of all types to give us answers. I don’t want to hear the politically correct response. I want to hear the truth. Does the glass make a difference in how the ADAS systems work? If so, how? If a system is so delicate and precise that a slight difference in the glass would cause it to malfunction, what about rain, snow, ice, fog, condensation, bug guts, sand pits, rock chips or anything else that affects driver vision? Do these factors affect operation as well? I will be updating you in future blogs with the information I discover.

I have another mystery that I am hoping you can help, especially my friends and colleagues in Europe.

The story:

My son is the glass manager for a large dealership group here in Madison, Wis. He and his crew do all the glass for his dealership and, like most dealerships, they use only OEM glass and follow OEM recommendations.

He was given an installation in a 1995 Porsche 911 Carrera two-door coupe to do and ordered the glass with the use of the VIN number from the vehicle. The glass in the vehicle is the original Sigla brand glass. The glass that arrived for replacement is a Pilkington Germany product with the Porsche logo that the dealership received directly from the OEM distribution center (Porsche part #99354111106). The original glass did not have a small third visor but the new glass did. This threw up a red flag so he checked with Porsche and found that the new glass was the interchange for the old one.

The FW791, which is the NAGS number for this particular vehicle, has a four-sided wrap-around frame with a rubber insert that attaches to it which overlaps the pinchweld. It fits into an “L” shaped pinchweld on all four sides. It comes with a built-in antenna and a VIN window. This is not a very difficult installation. You just need to remove the inserted moulding and cut out the glass. The problem with this vehicle is that the pinchweld floor is very narrow so the bead application must be perfect or the urethane will ooze into the vehicle.

Once the glass was cut out, the new glass was dry set and my son found that the glass was short side to side by almost a half inch on each side. My son called Porsche and confirmed that the right glass was sent and that the problem was in the installation. Thinking that the bead of urethane would change the fit slightly and that the moulding insert would cover the gap, he installed the glass in the opening and carefully applied the urethane bead to make sure the bead would touch the glass rather than the moulding. When he centered it in the opening he noticed the bead oozed into the vehicle and made a terrible mess. We also noticed that VIN window partially covered the VIN plate. Everything he did could not get the glass to fit properly. He ordered another glass thinking that there was a defect in manufacturing but that glass fit the same way as the previous one.

Then he called me. He asked me if I knew anything that could help in finishing this installation for his customer. I compared the old Sigla windshield with the new Pilkington and there is no doubt that the glass is not the same. So I began some research. Here is what I discovered.

Supposedly, Pilkington acquired Sigla and all of its data and equipment. I tried to find out the details of the sale but could not.

This particular vehicle had a windshield change mid-model year at the VIN number … 300000 and above. The Porsche windshield part number for vehicles with VIN under … 300000 is 99354191100. The windshield part number for vehicles with above … 300000 is 99354111106.

The 1995 model, according to NAGS, has a FW791 windshield and has an interchange of a FW2032.
Model years 1996-98 use a FW2032 without any interchange.

It seems that the only vehicle that uses a FW791 is the 1995 Carrera. Is there a difference in fit between a FW791 and the FW2032? Could it be that it is not a true interchange?

My son went to Chicago to find a FW791 to compare with the Porsche part. The FW791 XYG is the same as the Porsche Pilkington part, and both were short side to side by an inch from the original Sigla windshield.

The new Pilkington windshield has a third visor as mentioned above but we also discovered that the VIN plate was partially covered by the frit paint.

What does this all mean?

I don’t know but here is my opinion and take it for what it is worth.

If the 99354111106 is the FW2032 and the 99354191100 is the FW791, was there an assumption made that the FW2032 is the same as the 791 and there was no need to make them both?

My opinion is that when Pilkington purchased Sigla and the equipment and data, an executive decision was made to reduce slow moving parts and reduce inventory which any smart business would do. They assumed that the Sigla 791 was the same as the 2032, thus defaulting to the 2032 and eliminating the FW791 production and data. The problem is that they didn’t realize or didn’t notice that there was a slight difference between the two, namely the measurements side to side and the VIN window placement.

When we quizzed Porsche and Pilkington on this theory and with the fact that the glass did not fit, their response was the same. We have not had any complaints about this before. Which on the surface is a very good question, why haven’t we heard of this problem before 2015? In fact, we have. I personally dealt with a moulding fit problem on one several years ago and I read recently on™ forum of another tech having a similar problem. There has been problems but they have been few in number and the techs in the field have found ways to fix it.

Why are there so few? First of all, there were probably a few older produced 791s that had the correct measurements and were sold with no problems. However, as the older stock was depleted, the new defaulted 2032s took the place. The second half of 1995, ’96, ’97 and `98 models had a perfect fit because they used the 2032 as an OE part, again no reported problems. The only vehicle that needed the older 791 part was the earlier ’95 model. These were getting older and fewer in number. The vehicle is now 20 years old and I would guess that there are very few with a VIN under 300000 left. Of those, I doubt that there will be a lot of miles driven and windshields’ broke. This is why we haven’t heard too many reports of this particular problem before today.

As I am here writing this blog, my son called and said that he found a fix for the problem. He found a FW791 without a moulding. It is an aftermarket brand but by using a universal “J” moulding instead of the OE frame/moulding combination, he could achieve a proper bond and make the moulding look good. Now his only problem is to explain to the customer why an OE glass part does not fit better than an aftermarket one. This should be interesting.