Parts Decisions, Safety Factors and Your Liability

Unless you just woke up yesterday, you know the big news in the industry is the controversy over aftermarket (A/M) parts, specifically their use in structural and safety applications. This article is going to delve into the facts that you will need to consider before making decisions on repairs to collision-damaged vehicles. Many of you have seen the IIHS (Insurance Institute for Highway Safety) crash test video of the 2009 Chevrolet against the 1959 Chevrolet. The results of the video probably shocked you. How can the 1959 so-called "tank" collapse and perform so poorly against a late model vehicle that usually falls apart and is built like…well, you know what we are getting at. The answer is collision energy management.

If you have read our other articles in Hammer & Dolly, you have learned that we have outlined the importance of collision energy management built into today's vehicles to combat the forces applied to the vehicle during a collision. Crumple zones and reinforced areas are painstakingly designed and tested by design engineers to ensure that the vehicle's occupants are protected. The SRS (Supplementary Restraint System) components are designed to work in response to the vehicle's collision energy management system. SRS sensors and computer modules control the SRS seat belts, air bags and other safety features based on how the vehicle's structure responds to the crash. This might come as a shock to some of you, but the bumper reinforcement and radiator core support not only play an important role in collision energy management, but also assist in the way the SRS sensors evaluate the collision forces and the deceleration of the vehicle.

The bumper reinforcements in today's vehicles are comprised of structural aluminum, UHSS (Ultra High Strength Steel) or Boron steel. Radiator core supports can be comprised of MS/SS (Mild Steel/Soft Steel), HSS (High Strength Steel), fiber reinforced plastic or structural aluminum and can be welded on or bolted on. The choice of what type of material the reinforcement or core support is made of is dependent on the testing performed by the manufacturer's engineers during crash testing. The reinforcement, mounting brackets and radiator core support play an important role in how the SRS system will react during a collision. The SRS sensors in today's vehicles are very responsive and deployment decision-definitive. Most sensors use an accelerometer to measure the deceleration and then report this information to the airbag control module, which in turn decides if airbag (and/or seatbelt) deployment is warranted and what degree of protection is needed.

A major issue with using an A/M part is that many times, it is not even made of the same type of material as the OE part. There have been a few organizations and individuals who have conducted basic testing on randomly-chosen OE and A/M parts and made some comparisons. Some of the concerns reported included differences in material thickness, weight, shape and substrate composition. One of the simpler, non-scientific tests recently attempted was a comparison of a Toyota Corolla front bumper reinforcement and an A/M Corolla reinforcement. The test included an attempt to cut through both reinforcements with a reciprocating saw. The saw cut through the A/M reinforcement with little resistance, yet only scratched the OE reinforcement. The OE reinforcement is made of UHSS with boron alloying, and the A/M is made of Mild or High Strength Steel (HSS), which have different tensile and yield strength. This simple test shows a definitive difference between these two parts. This difference does suggest that installing the A/M part as part of the repair may alter, and adversely affect, the collision energy management and thus the response of the supplemental restraint system. Clearly, one series of tests on one component type does not establish that aftermarket components compromise the safety of the occupants during a subsequent collision, but it does justify the need for additional questioning and comparative testing.

Contrary to popular belief, radiator core supports are structural components and play an important role in crash management. Regardless of the support construction (fiber-reinforced Plastic, Mild Steel, HSS, aluminum or magnesium), it is considered a structural part. You may wonder how a core support made of "plastic" may be considered a "crash management" component. You must consider that some components are "sacrificial" and designed to limit the transfer of energy to the upper and lower uni-rails. The reason for this is to limit the amount of damage to the structural components in low-speed collisions (thus keeping the vehicle repair costs "low").

Recently, an A/M company hired the services of MGA Research Corporation, an engineering testing firm, to conduct Insurance Institute for Highway Safety (IIHS) low-speed crash tests (10 kph/6.2 mph) comparing an OEM and A/M front bumper on a 2006 Chevrolet Silverado. (Note: Most OEMs require tests at 16.09 kph/10mph). A review of the crash videos revealed a definitive difference in how the vehicles reacted during the crash. The videos are of a left side frontal view. The following is an analysis of the videos:

The OEM bumper: The front bumper shows evidence of a rearward deformity. The front grille, left front signal lamp and headlamp show evidence of little to no movement. The hood-to-left fender panel gap and the hood-to-left headlamp gap appear to have little to no change and no apparent deformities.

The A/M bumper: The front bumper shows evidence of a rearward deformity. The front grille, left front signal lamp and headlamp show evidence of forward movement during contact with the barrier. The left front signal lamp dislodged from its mounting location. The hood-to-left fender panel gap and the hood-to-left-headlamp gap appear to change during contact with the barrier; this movement shows evidence to support that the collision force moved the aluminum radiator core support rearward.

On the Web page from the A/M company, they state that the cost of repairs to the OE-equipped vehicle is $1,778.31, and the A/M equipped vehicle is $1453.84, for a savings of $324.47. We do not like numbers in this case, because numbers do not tell the whole truth. On paper, the cost savings is good, but you can easily see the vehicles do not react in the same manner during identical crashes in the videos. In addition, the tests and results do not appear to consider the response of the entire vehicle to the collision. If the vehicle structure responds differently to the collision, the response of the airbag system may also be different, thus altering the manufacturer's design regarding occupant protection. Without confirmation of the operational response of the supplemental restraint system during a subsequent crash, a savings of $324.27 may not be worth the risk.

Vehicles cannot be repaired based on cost (numbers) alone. The insurance company is only responsible to pay for the correct and proper repairs; the repairer is the professional and is solely responsible for the correct and proper repairs to a collision-damaged vehicle. Therefore, the components you choose to install are your responsibility. We are not suggesting that installation of A/M parts is an incorrect or otherwise "dangerous" choice. Until more scientific testing results are made available, just make yourself aware of the differences between OEM and A/M parts and the compromises, if any, that using A/M parts brings.

Hopefully, this article has brought to your attention the importance of making informed decisions regarding replacement parts and how those parts can affect your liability. Feel free to contact us at any time if you have any questions that we could help with.