New study examines dire consequences of a poor repair

For years, I've traveled the country speaking to repairers and shops about the absolute need for the collision industry to perform truly professional repairs – repairs made using up-to-date tools, quality parts and OEM repair instructions.

Unfortunately, too many shops continue to take a different path and conduct their business by performing work defined far more by low costs and questionable quality than the necessary dedication to what is right and best for our customers and the industry. Convincing folks on the wrong path to reassess their business philosophy can be difficult since they (and their customers) may not be aware of just how dangerous unprofessional repairs are.

That may be changing – I hope!

A while back, I received a report form Aaron Schulenberg, the executive director of the Society of Collision Repair Specialists, about a collision repair study conducted by KTI GmbH & Company in Germany. The study, available in its entirety at the SCRS website (www.scrs.com), looks at a late-model vehicle that is crashed and then repaired using tools, parts and procedures that are both "non-professional" and way too common. The vehicle is then crashed again, and the damage is analyzed. The result is no big surprise – due to substandard repairs, the vehicle doesn't react as it should during the second collision to protect passengers. In fact, it puts them at serious risk.

Let's take a look at the study and what we should all learn from it.

Study background

The study utilized a 2005 VW Passat that incorporates ultra high-strength steel reinforcements in its rocker and B-pillar. The Passat received a side impact at about 30 MPH. Technicians then conducted repairs with used parts, MIG welds and an older squeeze-type resistance welder. Perhaps most significantly, they did not use any current OEM replacement data. Instead, they utilized commonly accepted collision repair methods, which the study refers to as 10-year-old repair methods.

A 2005 Volkswagen Passat: A German study examined how "non-professional" repairs on the popular late-model vehicle would affect its collision protection systems in a subsequent accident. (IMAGE / VOLKSWAGEN)

Both side impacts were conducted as follows:

• The car was damaged by a side impact similar to an intrusion by the front of another car into the passenger side of the test vehicle, using side-impact model tests of the Euro NCAP.
• After the repair, this vehicle was involved in a follow-up crash simulation in the same configuration with a side impact on the repaired passenger side, at the same speed.

After the initial crash, the study reports the following damage:

"During the side impact, the car was severely damaged on the passenger side, as intended. The sill and the floor/undercarriage behind it were particularly distorted. Additionally, the doors and the B-pillar were considerably damaged. There was no damage to the screen pillar or windscreen glass. The pyrotechnic protection/restraint systems (front and rear passenger side airbags, front passenger belt pre-tensioner and passenger side curtain airbag) were correctly deployed. Overall the car body structure deformed and behaved as expected. As well as the visual analysis, electronic measurement of the car body was carried out. This showed the maximum intrusion to be 161 mm."

In short, the vehicle performed just as it should have during this kind of collision. It sustained significant damage, but if this were an actual accident with real passengers, they would have received as much protection as the vehicle was designed to give.

Substandard repair details

The repairs used to fix this vehicle are exactly the kind I warn shops about. On the outside, they appear to bring the vehicle back to pre-accident condition. Appearances are deceiving since these repairs don't restore the pre-accident collision safety and protection capabilities like a professional repair would.

The vehicle in the study received a 30 MPH side impact, was fixed not following OEM standards, then side-impact tested again. (IMAGE / FORD)

The study points out that the damaged car was repaired with an older spot welding machine with fixed pressure and 6.4 kA maximum current.

Note here that the OEM recommends using an Inverter-type welding machine with 10 kA maximum current and a variable pressure (maximum 10 bar) to join the high-strength steel safely.

Changes in the recommended material strength and structures can impact the level of protection a vehicle can provide. Note the number of airbags and crumple zones in this example and consider how changes to the vehicle could impact them. (IMAGE / FORD)

Perhaps more significantly, the deformed inner sill, made from ultra high-strength steel, was re-shaped and partially replaced on a bench then re-fitted using a MIG welding process.

A professional repair, based on OEM recommendations, stipulates replacement of the B-pillar and other deformed structures with components made from high-strength steel. A partial repair of such steels as done here is not acceptable, since the substandard welding and reforming of the parts severely degrades the strength of the materials and therefore the strength of the structure.

Post repair crash report

This loss of strength is immediately evident in the follow-up test collision. The study notes:

"It was immediately evident that there was a substantial difference, with far more comprehensive deformation of the car body after the second impact. The B-pillar had noticeably higher intrusion into the passenger compartment in comparison with the first crash, especially at the lower part at the connection with the sill. Later measurements of the car body confirmed there was 60 mm more intrusion after the second test, compared to the first crash."

Think about the "noticeably higher intrusion into the passenger compartment." Do you suppose this intrusion might seriously injure or kill a passenger? Would you want to be responsible for this repair?

The study also made use of crash photographs, high-speed crash movies and electronic measurement of the car body. This analysis clearly showed higher intrusion at the same moment in time in the second crash test.

The study results go on to note more damage resulting from the unprofessional repairs:

"Other differences were noticeable at the rail/roof and the transmission tunnel, which both displayed severe deformation not seen in the first crash. It seems that the load paths were quite different in the second crash. It was also notable that the top right corner of the windscreen was damaged in the second crash, further indication of changed load paths.

"These comparisons made it evident that a change of load paths and therefore of the energy dissipation was due to the unprofessional repair. The pyrotechnic protection/restraint systems (front and rear passenger side airbags and the front passenger belt pre-tensioner) were correctly deployed but the passenger side curtain airbag failed to operate."

You heard that right – the passenger side curtain airbag didn't deploy. If this fact and the increased level of intrusion together don't indicate how much danger passengers would have been put in, consider one more study finding:

"After removing all the seats and necessary trim, the deformation of the transmission tunnel after the second test was clear to see. The cross-member which supported the front seat had pushed into the transmission tunnel, distorting it severely. In comparison, there were no measurable changes at the transmission tunnel during the first attempt."

Study's conclusion

The study pointed at all the problems with an unprofessional repair. Though these problems are pretty obvious, I think it's important to repeat what the study says shops must do to avoid them.

It states:

"New materials mean that body shops must continuously ensure that they are conversant with the requirements for new tools, procedures and information about the repair processes. New welding machines need to be used, training is required and OEM information has to be accessed to make sure that the correct repair methods will be applied. Without this knowledge, it is likely that an inadequate repair will be the result, potentially placing the car and its occupants at much higher risk in a later crash.

"Taken together, the technical progress made by the OEMs has resulted in corresponding new challenges for the repair shops. Repair shops must ensure they have well-trained staff and are equipped with appropriate tools to cope with the techniques needed for professional repairs on today's cars when they are damaged in an accident. If such techniques and knowledge are not available, a nonprofessional repair may lead to a significant reduction in the safety and quality of these cars."

The study further notes that non-professional repairs are the product of any or sometimes all of the following:

• incorrect method and/or sequence of repair;
• poor assembly of correct/incorrect spare parts, components and sub-systems;
• fitment of low-quality spare parts, components and sub-systems;
• incorrect assembly and connection of electrical/electronic systems and sub-systems;
• absence of correct, special or custom tools; and
• repair of damaged parts when actual replacement is necessary.

Is your shop guilty of any of these faults?

I encourage all of you to read the entire study and share it with your employees, colleagues, customers and others. As always, I strongly urge you (repair owners and managers) to print out the OEM's recommended repair procedures and give them to your techs and estimators. The risks and liability associated with not following OEM procedures are serious. Think about the safety of your customers.