Vehicle Repair Industry Standards Exist for a Reason


R. Scott King, BSME, Principle Automotive / Mechanical Engineer ::::
Vehicle repair industry standards exist primarily to promote the safety of the women and men that service passenger vehicles and commercial trucks, as well as that of the motoring public in general. Sometimes, however, these standards can protect the misfortunate few, who by improbable circumstances, are exposed to risks that often accompany a seemingly benign vehicle repair procedure.
Consider for example the case of a commercial truck owner who had taken his truck to a local repair shop to diagnose a complaint of loose steering. With his shop filled with other vehicles, the mechanic elected to perform the inspection outside his building in an area not subject to customer proximity restrictions. While the mechanic was replacing the worn steering component, the curious truck owner was standing behind the kneeling mechanic to observe the process. Continue reading “Vehicle Repair Industry Standards Exist for a Reason”

Pet Safety in the Car

Animal Safety in Cars

As an engineer who deals with occupant safety in vehicles, I occasionally get asked questions related to vehicle pet safety. Earlier this year, the topic gained attention when a Maine state legislator introduced a bill to require dogs to be harnessed or tethered in a moving vehicle. The bill was later withdrawn, but the questions remain. Some states have laws on the books to address issues with drivers who operate their vehicles with a dog on their lap. Frequently, this is related to the risk of the dog distracting the driver or interfering with the operation of the vehicle. A 2012 New Jersey law makes it illegal to transport an animal in “a cruel or inhumane manner”; however, this has led to many questions as to what constitutes “a cruel or inhumane manner”. Only Hawaii prohibits driving with a dog that is free to move about the vehicle.

When asked about the safety of using a harness to restrain dogs in a vehicle, the initial response is to ask whose safety they are concerned with, as the answer can be different. There are many different animal restraints on the market, and prices vary widely. If the concern is preventing the animal from being able to climb up into the front seat, distract the driver or interfere with operation of the vehicle, just about any of the systems will serve that purpose. If the concern is to prevent a dog from falling or jumping out of a car window, there are fewer capable of that task; many systems though can keep Fido from exiting the vehicle. The real issues arise when the question is the ability of the pet restraint to function properly in the event of a crash.

There are two factors related to harnesses. The first is the ability of the harness to prevent the animal from becoming a projectile and striking other occupants. This is a relatively simple issue; the harness just needs to be capable of limiting movement of the body of the pet and carrying the crash loads from the weight of the pet. In 2013, the Center for Pet Safety (CPS) tested several harnesses which claimed to offer crash protection to pets. Their focus was on the integrity of the harness during the test, and the ability of the harness to limit the head excursion of the test dogs. Most of the harnesses tested by the CPS were not capable of keeping the test dogs on the seat. Many of the harnesses had components or were assembled in a way which made them incapable of remaining together and able to transfer the crash forces to the vehicle. They allowed the test dogs to have excessive motion; in a real vehicle, this would have allowed them to impact other occupants or the interior of the vehicle.

The second, and more difficult factor, is the ability of the harness to protect the pet from injury. To protect the restrained pet, the system must not only be able to carry the crash loads, but also apply those loads to the animal in a way which will not cause injury. Just as with people, this means the restraint forces must be distributed over as wide of an area of the animal’s body as possible, and the harness loads must be applied to the strong, bony parts of the animal’s body. One of the more difficult items to control is how these loads are applied to the body. With adults, we have some basic expectations of how they will or should be sitting in a car. For young children, we try to limit or control the child’s position with the use of a child seat with a harness. For an animal, the task is more difficult, and their initial position can vary widely unless the harness controls or limits their ability to move. Additionally, there are issues with being able to measure and compare forces in the body of the animal with their tolerance to injury.

Another issue causing so much confusion with pet restraints is the lack of regulations. While many manufacturers make claims that their products offer crash protection, when the CPS tested the products, most did not deliver an acceptable level of protection. Pet restraints are not regulated by the government. In fact, the Consumer Products Safety Commission (CPSC) and the National Highway Traffic Safety Administration (NHTSA) have both stated pet restraints do not fall under their jurisdiction.

So, do you think you can avoid all this confusion, skip using a harness and just place your pet in the pet carrier you have been using for years? Not quite. In the CPS testing, many of the pet carriers tested structurally failed and allowed the test dogs to be ejected from the carrier. The test results for crates were somewhat better in that most were able to keep the test dogs contained in the crates. However, some still had issues with remaining attached to the vehicle.
All that being said, what is the best way to restrain your pet in the car? The American Veterinary Medical Association recommends you consider if you really need to take your pet with you in the car. If they really don’t need to go with you, then leave your pet safely at home.

If your pet must join you in the car, based on the available information, your best option is to purchase a harness, carrier or crate that has been crash tested and shown to have the ability to remain intact, and limit the motion of the animal during a crash.

Additional Resources: The Ultimate Guide To Moving Long Distance With Pets

Child Seat Cold Weather Safety

John R. Yannaccone, PE, Senior Mechanical Engineer ::::
As the weather starts to turn cooler, the need to add layers to keep warm begins. However, everyone needs to make sure the added layers do not compromise safety. This is especially true when it comes to children who are in child seats. While we all want our children to stay warm during a car ride, we need to be sure we are doing it in a safe way.
One of the major problems seen is dressing children in bulky or puffy coats. As the general rule, bulky coats should not be worn under the harness of a child seat. These coats prevent the harness from being tightened to the child’s body and compromise the safety of the child seat by reducing the effectiveness of the harness.
Frequently, the next question people ask is, “How do I know if my child’s coat is too bulky?”
There is a simple test you can perform to see if your child’s coat is bulky, and will cause the harness to be less effective. Start by putting your child’s coat on them, place them in their child seat, and tighten the harness. A properly tightened harness is one that you cannot pinch the harness webbing between your fingers.
Next, without loosening the harness adjustor(s), unbuckle the harness and take your child out of the child seat. Take your child’s coat off and place them back into the child seat and buckle the harness without adjusting the straps. Try and pinch the webbing as you did before. Is there more slack than there was when your child had their coat on? If so, the coat is too bulky to wear under the harness. The slack you see is what would be seen in a crash when the puffiness of the coat is compressed by the forces of the crash, and would reduce how well the harness restrains your child.
So how do you keep your child warm in the car if they have a coat that is too bulky to wear under the harness? Following are some options:

  • See if you can find a less bulky coat, i.e. a thinner fabric like an insulated sweatshirt or fleece coat which can provide warmth without bulk.
  • Have your child remove their bulky jacket before they get in the child seat. After harnessing them in, cover them with a blanket. This is a good method if you are using a carrier style child seat since you can harness the child in and cover them with a blanket before going outside.
  • Rather than a blanket, you can also place the child’s coat on them backwards after they are harnessed into the child seat. In this case, the coat serves as a blanket with arms.

Remember, no matter which of these options you choose, harnessing a child too loosely in their child seat is one of the most common errors made. Leaving slack in the harness will increase the movement of a child in a crash, and can even allow them to be ejected from the child seat. You still need to tighten the harness so you cannot pinch the webbing. Taking these steps will help keep your children warm and safe during your travels in colder weather.
John R. Yannaccone, PE, Senior Mechanical Engineer with DJS Associates Inc., can be reached via email at or via phone at 215-659-2010.

Automotive Infotainment & Telematics: What’s Their Purpose & How do They Differ?


Robert S. Kinder, Jr., BSME, Automotive / Mechanical Engineer ::::
In the automotive industry, vehicle technology continues to advance to satisfy consumer driven functions. Whether the expectation is increased safety, comfort, or options, in-car technology demands are on the rise. One of the measures taken by automakers to mitigate these demands is the implementation of state-of-the-art infotainment or telematics systems. Although there is some overlap between these two systems, such as sharing the same visual display monitor, there are functional differences. The basis of infotainment involves the combination of entertainment and information, which may be obvious given the name “infotainment”. Common infotainment functions include GPS navigation, listening to music, and Bluetooth phone operations. More recently, infotainment systems have gained the ability to store cell phone related data when tethered by USB or Bluetooth. Infotainment systems also allow drivers to link their phones through integration software such as Apple CarPlay and Android Auto.
Vehicle telematics merge telecommunication and informatic functions. When comparing telematics and infotainment, the most notable difference is that telematics utilize two-way communication. The communication provides a platform to send and receive data. The exchange of data is necessary for features like vehicle location for navigation, collision reporting for police or insurance providers, and remote vehicle diagnostics. Telematic systems can be built-in (onboard) or aftermarket. Built-in or OEM telematics are commonly subscription based such as OnStar by GM. Companies are beginning to use aftermarket plug-in telematics to track their vehicles and how or where they are driven. The devices are plugged into and powered by the diagnostic port usually located in the driver’s footwell area. Insurance companies offer similar devices to track driver behavior to possibly yield a discount on premiums.
Regardless of the type of system, infotainment or telematic, accessible data is potentially stored in the vehicle or in a cloud. The data is not only obtained for insurance discounts or safety related purposes, but also for incident related situations being investigated at a forensic capacity.

For additional information on Infotainment & Telematics, or to arrange a presentation, contact Robert S. Kinder, Jr., BSME, Automotive / Mechanical Engineer with DJS Associates, at or via phone at 215-659-2010.

Headlights: An Overlooked Safety Feature?

Robert T. Lynch, PE, Senior Mechanical Engineer ::::
With today’s vehicles boasting new safety technology such as blind spot detection, autonomous emergency braking, and lane keep assist, headlight performance is often an overlooked safety feature only considered as an afterthought once the vehicle leaves the sales lot. For a technology that has existed (and been improved upon) for over a century, the average car buyer has undoubtedly developed a false sense of security when it comes to new vehicle headlights expecting the lighting technology to be state-of-the-art and provide sufficient illumination to light up the roadway at night.
However, recent testing by the Insurance Institute for Highway Safety (IIHS) has revealed that the headlights on many new vehicles do not provide enough light for a driver going 55 miles per hour on a straight road at night to stop in time after spotting an obstacle in his or her lane. Of the 269 headlight systems (Halogen, High-Intensity Discharge, LED) tested in 129 model year 2017 vehicles, more than half were rated marginal or poor. And buying an expensive vehicle, which is often associated with better safety performance, does not guarantee decent headlights. For the mid-sized SUV market, the Hyundai Santa Fe received a good rating while the Infinity QX60, with a base price of nearly $15,000 more than the Hyundai, received a poor rating. Continue reading “Headlights: An Overlooked Safety Feature?”

Hitching a Ride on the Lift!

John R. Yannaccone, PE, Senior Mechanical Engineer ::::
Case Synopsis: Two painters were operating a telescopic boom lift on a commercial building construction site. The painters were about to break for lunch when a repairman, also working on the roof, asked the painters for a ride to the ground so he wouldn’t need to go to the other side of the building and descend a ladder. The lift operator moved the platform into position so the repairman could climb onto the lift platform. When the repairman climbed on, the lift began to tip over causing the repairman, and the painters, to fall to the ground. The repairman sustained serious injuries while the painters sustained only minor injuries.
Expert Analysis: Analysis in this case revealed the weight of the two painters and their equipment was within the safe load limits for the full operational range of the lift. The two painters were wearing proper fall protection harnesses attached to designated anchor points inside the lift. When the repairman entered the lift, the additional weight exceeded the safe operating capacity of the lift at the extended position, and then tipped over. Continue reading “Hitching a Ride on the Lift!”

What’s That Ticking Sound in My Engine?

R. Scott King, BSME, Automotive / Mechanical Engineer ::::

As consumers of automotive repair services, we know that from time to time a mechanic might not always fix it right the first time. Whether it’s an annoying dashboard squeak or the mysterious “Check Engine” light that shyly disappears on our way to the service shop, mechanics sometimes need a second shot at an effective repair. However, what about a third or fourth attempt, or even more? How patient is too patient and what recourse is available upon reaching patience’s limit? Most people likely do not yet know the answers to these questions and with luck never will, but some unfortunates do, having found their answers through their own experiences. The following is what happened to a recent client.
Initially happy with her auction lot purchase, the new owner took her vehicle to a local dealer for routine maintenance and a “once-over” to ensure the vehicle was safe and reliable. Additionally, she asked the mechanic to investigate a minor “ticking” sound coming from the engine. At the dealer’s suggestion, the car owner purchased a one-year used-car warranty to insure against major repair costs. All routine maintenance and inspection services were performed to her satisfaction; however, the mechanic did not attempt to repair the “ticking” sound. Rather, referencing a manufacturer’s Technical Service Bulletin written to assist diagnosis of similar customer complaints, he suggested the noise was normal and likely related to the fuel injectors. Although a plausible explanation, the noise persisted and worsened. Over the course of the eighteen months, she returned to the dealer five times for routine service each time complaining about the ever-louder “ticking” noise. Finally, and only when her vehicle would no longer run requiring a tow-truck’s help getting to the dealer, did the mechanic there report the unwelcomed although predictable news; she needed a new engine. Continue reading “What’s That Ticking Sound in My Engine?”

Child Safety Seat Fails to Deliver Safety

John R. Yannaccone, PE, Senior Mechanical Engineer ::::
Case Synopsis: A vehicle stopped at a red light was struck from behind by another vehicle. The impacted vehicle had three adult occupants, and a child harnessed into a rear facing infant seat. During the crash, it was reported that the carrier portion of the infant seat (with the child in it) separated from the installed base. As a result, the child and the carrier moved inside the vehicle and the child struck their head and sustained skull fractures with an underlying brain injury. None of the other occupants had any serious injuries.
Expert Analysis: At the time the expert was retained, both vehicles were no longer available; however, there were sufficient photographs for a reconstruction to determine this was a moderate severity collision. The child seat was available for inspection and there were generally no signs of any substantial loading to the base or the carrier, which is consistent with it not being restrained during the crash. There were some areas of minor material deformation in an area that should not have been loaded.
The mother testified she installed the child seat, and the carrier was latched into the base on the day of the incident. She had no idea why the carrier would not have been attached to the base at the time of the collision.
An exemplar child seat, the same design as the one in the crash, was used for an analysis and showed that the carrier was misaligned with the base. It was possible to have the attachment hooks contact the area, not intended for latching, which showed the minor deformation. If this occurred, it would appear to the user that the carrier was latched to the base, and capable of taking the type of loads a parent would apply to verify the base and the carrier were attached; however, it would be unable to carry the loads of even a moderate crash.
By making very minor modifications to the carrier, this additional location where the attachment hooks could improperly attach could have been eliminated. This would leave only the appropriate locations for the hooks to engage thereby preventing the risk of a false latching between the carrier and base from occurring.
Result: A case was pursued against the child seat manufacturer for the design of the child seat, which allowed the carrier to be installed in this improper position such that it was unable to sustain the loads of a crash. The case settled prior to trial.
John R. Yannaccone, PE is a Senior Mechanical Engineer with DJS Associates and can be reached via email at, via phone at 215-659-2010 or via

Motorcycle Handlebars: More Important Than You Think!


Robert S. Kinder, Jr., BSME, Automotive / Mechanical Engineer ::::
The handlebars are a critical component when it comes to maintaining control of a motorcycle. Whether the rider is accelerating, braking, or employing techniques such as counter-steering, a properly secured handlebar is necessary to complete such tasks. If the handlebars were to come loose or detach, could you maintain control?
Yamaha has recently recalled over twenty thousand late model motorcycles due to a painting issue that can result in the loosening of the handlebars. According to the National Highway Traffic Safety Administration (NHTSA), a handlebar that is not properly secured to the motorcycle can cause a loss of control and increase the risk of a crash. The handlebars are clamped by a metal holder. It turns out that if an external force is applied to that holder, the paint can wear off over time. As the paint wears off, a space is created between the holder and mounting surface, thus reducing the clamping force on the holder. The combination of the newly created space and engine vibration can cause the holder’s stud bolts to loosen. Not only can the studs potentially loosen, the holders/handlebars can even fall off. Thread-locking material is commonly used to prevent the loosening of bolts due to vibration, however NHTSA indicated that the holder may lack adequate thread-locking material. If the bolts were to loosen or fall off, the handlebars can become detached from the rest of the motorcycle. Continue reading “Motorcycle Handlebars: More Important Than You Think!”