by Bob Beranek

I have been involved in some discussions recently concerning value-added accessories on automobiles, and specifically automotive glass as it pertains to safety and/or performance. Anyone who knows me would say that I usually fall on the side of safety over performance. However, it is not as black and white as it might seem. As a matter of fact, most of the items that have been added to the modern automobile represent a little bit of increased safety and a little bit of increased performance—blurred lines.

The fact is that safety items are government regulated and performance items are not. If a car company has a choice of labeling a value-added item a “safety” device or a “performance” device it would weigh the profit advantage of each and come up with a decision that benefits the bottom line. If an accessory improves safety, that value will be there regardless as to how it is labeled, but by calling the add-on a performance feature, car companies can avoid regulation and possible liability.

What does this mean? It means that if a value-added item can be labeled as both safety and performance, it will be labeled as performance.

I alluded to this phenomenon a few weeks ago when I wrote about laminated door glasses. I questioned back then whether a laminated door glass was a safety device or a performance feature. The National Highway Traffic and Safety Administration (NHTSA) saw the same blurred lines and backed away. Since then, I have been asked numerous questions about other items added to the modern day vehicles such as Heads-Up-Display (HUD), rain sensors and special urethanes. For the next few posts I will voice my thoughts on the matter and try to clear up the blurred lines of safety versus performance.

Special Adhesives

Let’s start this off with a material we are familiar with but are unsure how it should be labeled—special urethane. By special urethane I mean high modulus and low-conductive. Are these safety products or performance products?

If you ask the vehicle manufacturers, high modulus urethane is used for solidifying the body and boosting the performance characteristics of the driving experience. High modulus urethanes are stiffer when cured so when it is paired with other performance characteristics of the body assembly, it makes the unibody vehicle stiffer and improves handling on the roadway. So it is definitely a performance feature, right?

Now ask the collision experts. If a vehicle is involved in a collision with all of the body panels assembled properly, the crash dynamics are predictable and meet the safety standards put upon the manufacturer. However, if the panels are repaired differently than the engineers dictate, the result could be significantly different and possibly dangerous. The windshield and all the stationary bonded glass parts are structural panels that must be assembled properly for the vehicle to be safe in a collision. If stationary parts are installed in the aftermarket using regular modulus adhesives when the manufacturer assembled the vehicle using high modulus, could performance in a collision be compromised? This sounds like a safety issue, doesn’t it?

Let’s look at another example. These days we see many more vehicles with aluminum bodies, with windshields that are installed with low-conductive urethane at the factory. If you ask vehicle manufacturers, low-conductive urethane is used to limit the interference of electrical systems like an antenna or defogger. This makes some sense because regular urethane is primarily carbon black that conducts electricity. Therefore, if it is used in bonding a glass part to a vehicle where it has contact with electrical components, it could interfere with electrical performance. Low conductive urethane is then a performance material, right?

Now ask a mechanical engineer. When two dissimilar metals come in contact with each other the result is what is called galvanic corrosion. If regular urethane, which is primarily carbon black, is applied to an aluminum vehicle body, the possibility of two dissimilar metals (carbon black to aluminum) coming in contact is higher than normal. This may cause corrosion which causes deterioration of the vehicle body, undermining the bond of the glass to the vehicle body. If this vehicle is involved in a collision, the windshield or other bonded stationary parts would not perform according to design, potentially putting the occupants in danger. This sounds like a safety issue, doesn’t it?

Blurred lines are everywhere in our industry. I suggest we use our heads and think it out. If we do, we cannot go wrong. Err on the side of safety and your sleep will always be restful.

“Shortly after I wrote my last post concerning exterior rearview mirrors, I got a call from one of my I-Car training colleagues asking a question about interior rearview mirrors. His question concerned the portion of the standard which he felt required the mirror be released from the mounting pad by the airbag deployment. I corrected him about the airbag part of his inquiry because the airbag is not in the standard.” —Bob Beranek

It says:

S5.1.2 Mounting. The mirror mounting shall provide a stable support for the mirror and shall provide for mirror adjustment by tilting in both the horizontal and vertical directions. If the mirror is in the head impact area, the mounting shall deflect, collapse or break away without leaving sharp edges when the reflective surface of the mirror is subjected to a force of 400 N in any forward direction that is not more than 45° from the forward longitudinal direction.

The 400 N represents 400 newtons, which is a measurement of force which is close to 90 lbs. (to be exact 89.923577548 lbs.) This means that the interior mirror is required to be released from its mounting by a force of 90 lbs. This is to protect the occupants from injury by the rearview mirror and/or mounting in the case of a collision. The older mirror mounting were so firm that serious injury was caused not by the windshield but by the mirror mounted to the windshield. So vehicle manufacturers had to build their vehicles with “break-away” mirrors since the 2000 model year.

The above are the facts related to interior rearview mirrors according to the Federal Safety Standards, but the reality of true mountings is something that confuses me. As a technician who has removed thousands of supposedly “break-away” mirrors, I find it curious that there are so many mirrors that take special tools, techniques and plain brute force to remove from the pad. There are ¼ turn mirrors, underside clips and others that take a concerted effort to release. Do these mirrors meet the requirement of breaking away by 90 lbs.? Shouldn’t they just pop off with upward or downward pressure of 90 lbs. or more? You would think so, but I fear that the standard isn’t being enforced.

There are still plenty of mirror mountings that do meet the standard. What happened? Did designers and engineers bow to the demands of consumers who complained of loose or vibrating mirrors? What about the federal government standards? Like all government agencies, they are dependent on the funds budgeted. If government doesn’t have the money to hire analysts and auditors to keep track of minor infractions, they depend on corporations to regulate themselves. They may require reports to be filed, along with data to prove the reports, but is the manpower available for follow-up? I believe that like so many other things that fall between the cracks, the rearview mirrors in automobiles are not on the government’s safety radar until serious injury occurs.

What do I believe? I believe that mirror designs work on paper but not in reality. I believe that the government regulators mean well in writing safety standards but don’t do well in enforcing them. I believe that mirrors are supposed to be removed relatively easily, but we still need tools, techniques and brute force to remove them.

So to my friends that suffer through the rearview mirror removal of automotive glass installation, you have my sympathy. I doubt seriously that the mirrors will automatically be easier to remove in the future. On the contrary, I believe that they will be harder to remove because the customers demand for firm mountings and fewer vibrations. But keep you hopes high, we always come through with innovative ways to get the job done.

I saw an interesting recall recently and thought I would pass it your way. It is concerning the Chevrolet Caprice and SS models for the model years 2013-14. The windshield wiper motor is stripping the teeth off the gears causing the wipers not to work. If our customers ignore or fail to get the recall notice shortly after the windshield is replaced, they could place blame on you if the wipers fail to work.

It is important to make copies of this recall notice and distribute it among your technicians so they have the facts in front of them in case the issue arises.

Report Receipt Date: June 27, 2014
NHTSA Campaign Number: 14V375000
Potential Number of Units Affected: 4,794

Vehicle Make, Model, Model Year(s)

·        Chevrolet Caprice 2013-2014

·        Chevrolet SS 2014
Manufacturer: General Motors LLC


General Motors LLC (GM) is recalling certain model year 2013-2014 Chevrolet Caprice vehicles manufactured June 7, 2013, to May 29, 2014, and 2014 Chevrolet SS vehicles manufactured September 13, 2013, to March 4, 2014. In the affected vehicles, the windshield wiper motor gear teeth may strip causing the windshield wipers to become inoperative.


Inoperative wipers will not clear rain or snow, reducing the driver’s visibility, increasing the risk of a crash.


GM will notify owners, and dealers will inspect the wiper module assembly and replace any affected ones, free of charge. The recall is expected to begin in early August 2014. Owners may contact Chevrolet customer service at 800/222-1020. GM’s number for this recall is 14295.