Estimating considerations for modern vehicles

Aug. 30, 2016
How do the changes in vehicle structure affect estimating and repair strategy? Let’s take a look at the “cause and effect” of these changes and why estimate writing increasingly requires an in-depth knowledge of repair.

Recently, I responded to a forum with an opening statement: “What the heck is going on? Cars haven’t changed much, but lately I’m seeing all of these supplements.” In my career, the past 10 years have offered far more change at a faster pace than ever before in terms of vehicle structural design. While features such as electronics, connectivity, creature comforts and power have changed, the most alarming change is far less visual — it’s structural. So how does this affect estimating and repair strategy? Let’s take a look at the “cause and effect” of these changes and why estimate writing increasingly requires an in-depth knowledge of repair.

Remember the days of following general sectioning guidelines and procedures? Well that‘s pretty much history now. Over the course of my career, I’ve performed thousands of structural repairs and sectioned hundreds of frame rails by simply using a common sense approach of following general sectioning guidelines, but not anymore. With today’s vehicles, I will not consider a structural repair without a knowledge of metallurgy, OEM position statements, and model-specific procedures from the vehicle manufacturer. So what happened? Advanced materials used in structures have progressed at an amazing rate, offering additional strength with less weight. Then there’s the Ford F-150 with its all-aluminum body, so even more change.

As more stringent fuel economy requirements are enforced, several vehicle manufacturers have chosen to combine advanced materials to reduce vehicle weight, as shown on this BMW body, which is primarily constructed of carbon fiber and aluminum.

First, let’s look at some of the properties of  advanced high-strength steel materials. There are several ways that we can describe the varying strengths of steel, with the most common being tensile strength. Tensile strength is the maximum amount of force that can be applied before the material fails (fractures). We are accustomed to finding a tensile strength rating listed in pounds per square inch (PSI), but it is much more common to see it listed in Megapascal (MPa), the metric equivalent, in most collision repair manuals or vehicle manufacturer’s publications. A comparison between the two measurements from psi to MPa is 1 MPa = 145.038 psi, while 1500MPa = 217,556psi. You may also recall in general sectioning guidelines that repairability of mild steel rated to mid-60,000 psi was excellent, and high-strength steel (HSS/HSSLA) was defined as beginning at 70,000 psi repairs were more tentative and varied with OEM statements, while ultra high strength steels (UHSS) beginning at 100,000 psi was considered non-repairable. It’s hard to imagine 1,500 MPa strength, as compared to vehicles of the early century, but it’s here, and we need awareness before repairs can begin.

Regarding specific advanced materials, it’s relevant for us to consider that any advanced structural material will have specific characteristics, as well as repair and /or replace procedure considerations, along with all kinds of names and terminologies. The terminology is an important consideration. Most structural repair procedures or the vehicle manufacturer’s repair/service information will contain an area that defines the steel type that is used on specific vehicles, as well as the repairability and limitations. Perhaps the first step when writing an estimate to perform a structural repair would be to obtain the vehicle manufacturer’s procedures to identify the material type. When writing an estimate, the following should be considered:

Is repair an option, or is replacement necessary? Then if replace, can it be accomplished through a sectioning location or must it be installed in its entirety? Consider what happens to a repair plan when the B-Pillar reinforcement requires replacement. Often we end up cutting an access hole in the upper roof rail aperture to access the weld mount locations. Now we implicate damage to the roof panel when re-installing the window cut, not to mention the additional R&I operations.

How about a few common vehicle examples? What does the 2015 Camry have for metallurgy? The front lower rail is 440MPa HSS, and inner rocker and upper B pillars are 440MPa HSS/980MPa UHSS/590MPa HSS. Examples of some mixed materials of aluminum and advanced steels can be found in the 2016 Cadillac CTS, where a cast aluminum front wheelhouse is rivet-bonded to the aluminum lower frame rail and tied into the Dual Phase (DP) A-Pillar extensions. The rocker panel reinforcement is not to be repaired or sectioned because it’s UHSS per GM position statement. Another popular vehicle example is Honda’s use of 1500MPa steels in 8 major structural areas in the “ACE Designed” Civic and qualify their repair with the following statement: Honda’s statement regarding: “1500MPa steel parts must be replaced at factory seams using squeeze-type resistance spot welding (STRSW). Do not section these parts!”

Structural adhesive and GM-approved rivets are used to attach the upper frame extension and the cast strut tower on the 2016 Cadillac CT6.

Not only is there a variety of mixed materials for structural enhancements, replacement procedures can vary widely depending on materials and OEM approaches. Before attaching a structural component, additional homework is required. Although the OEM attachment method may have been spot-welds, the replacement call-out can range from replacement spot-welds, weld-bonding, rivet bonding, plug welds, MIG brazed slots, double plug MIG brazed or some combination of any of the methods mentioned.   

So what does this do to our estimating and repair plan? What was once considered a repairable panel may now require replacement, depending on OEM position statements of repairability. Is it possible to build a responsible repair strategy without doing the homework first? After all an estimate could also be considered the repair strategy.

One of the first barriers is the fact shops are pressured to generate an accurate estimate within hours of the damaged vehicle entering the collision repair facility. Is it plausible that if we only write for what we see, we’ll be considerably far off the mark with our starting point? What about taking the vehicle apart, and then preparing then estimate? This is better, but we still need to do our homework before developing a true repair strategy. With an OEM position statement of “Do Not Repair” to an inner B-Pillar reinforcement, comprehensive measuring would also be needed to identify if it is, in fact damaged. Utilizing comparative measurement points on hinge bolts to compare the damaged side to the undamaged side could determine if the inner reinforcement has moved.

Advanced materials have changed the process of how repairs are performed, and what can or cannot be repaired. Don’t forget that occasionally there will be scenarios where layered outer panels are on top of inner panels beyond the access locations needed for inner panel replacement. Will this require outer panel removal to replace a damaged inner panel?  The answer is it depends: an inspection is required for layering and which adjacent panel is covering each other as this is generally not called out in most cases, causing an outer undamaged panel to be removed to access the inner layered panel.

So what’s the estimating answer? Here are some observations: before a repair plan is developed, OEM position statements, vehicle repair procedures, and damage information should be acquired and considered. Obtaining this information early in the repair process makes sense. Technicians will follow the repair instructions for correct installation anyway, so there is no need for a surprise later in the repair.

The blueprinting estimating approach can be an effective tool, but this process alone isn’t quite enough to solve all of the problems that arise when estimating a vehicle with advanced construction materials. Having different technicians dismantle and assemble a damaged vehicle can be counter-productive. Can a rotational approach be implemented where the vehicle’s primary repair technician is involved with the repair strategy early in the process by assisting the estimator during dismantling while the estimator obtains documentation to support the repair approach? This can create buy-in from the technician and fewer surprises without the frustrations about not understanding how things go back together when repairs near final assembly. This will create a valid “intelligent estimate” with few supplements.

Insurance companies need the d supporting information to verify correct repair procedures are adhered to, so that’s an upside to the early investment of time. If we think about it, isn’t a well-planned repair going to have positives like reducing cycle time and lowered supplement ratios?

What about the aluminum? It’s been around for years, but only became a viable player in the materials market when the 2025 CAFÉ standard of “54.5 by 25” was introduced. It’s lighter than steel and naturally resists corrosion, but how repairable is it? Answer: extremely.

Although the all-aluminum Audi A8 was built in 1995, and 15 other aluminum-intensive vehicles were released before the 2015 Ford F-150, little was done as far as training the current workforce. The optimism of aluminum coming to market in high numbers was not enough to convince collision repair facility owners to make the investment in training an equipment. Since the release of the  2015 Ford F-150, this has changed. There has been an increase in awareness from the estimating side of things, as well as a degree of retooling to accommodate repairs to aluminum intensive and aluminum/steel hybrid vehicles.

Aluminum panels vary from OEM in hardness and alloy mix, making some panels easier to repair than others. So how can the estimator predict hours of repair damage on aluminum panels? When compared to steel some additional time may be required for equal amounts of damage in appearance and as with all judgment times, it’s someone’s opinion. The good news is that with correct repair knowledge and tools, repairs are effective, productive and profitable for shops. As with all panel repairs, choosing repair is a business decision, but the math for aluminum panels favors repair since aluminum parts are typically more expensive than steel counterparts.

The complete cabin structure on the 2015 Ford F-150 consists of various aluminum stampings and extrusions.

Ford designed the F-150 with ample opportunity for collision repair options and offers access to procedures with PDFs hosted in a variety of locations at no charge to the public. For a repair facility, it means additional tool purchases, including rivet guns, dent removal tools, welding equipment, and dust extraction. Self-Piercing Rivets (SPR) are widely used from the OEM, so replacement options include SPR installations combined with bonding. Depending on the repair procedure, a solid rivet installation may be an option in some areas. Ford is against all other aluminum repair procedures.

Acknowledgement that steel particles mixed into an aluminum panel is a recipe for failure, separating the repair area from steel repairs prevents cross-contamination and the possibility of cross contamination between steel and aluminum, resulting galvanic corrosion. Ford allows curtains to temporarily segregate repair stalls, provided that the stalls are cleaned and tools are kept separated from steel repairs. A separate cabinet on wheels and/or tool packages on carts make that an easy task.

Repair planning is crucial when replacing a rivet-bonded panel. Installation must be completed while the adhesives are in the “open” stage, plus SPR’s expand within the inner panel, so exact lengths of rivets must be installed in the correct locations.

Regarding the F150, Ford requires technicians attend I-CAR’s “FOR06” prior to repairing the aluminum body truck, but estimators also need this information to properly prepare an estimate. Additionally, technicians need aluminum MIG welding training and certifications before attempting to weld on aluminum. One take-away from FOR06 for estimating includes Ford’s position regarding damage to cosmetic aluminum panels. Ford  states the part may be repaired if it is cracked or torn. No different than steel, right? As to structural: Ford’s position reads, “if any type of aluminum structural part is kinked, cracked, or torn, the part requires replacement.” This allows for repair depending on extent and location of damage. Most repairs to aluminum will require heat to the panel to temporarily soften the aluminum. When heating aluminum, Ford cautions not to exceed 425° F and to always monitor heat during repairs to prevent damaging the panel or destroying the adhesives between the panels.

Once trained and tooled up, technicians accustomed to repairing steel usually grasp aluminum repairs quickly and look at aluminum as an opportunity, not a barrier.

Estimating considerations for aluminum cosmetic panels isn’t much different from steel when inspecting for damage. OEM statements still apply: example Honda states “after aluminum dent repair, epoxy prime prior to body filler application”. With that in mind, we know cycle time may be longer for repair verse replace, and deserves consideration during estimating. Generally speaking, aluminum outer panels are considered cosmetic which allows for repair if is cost-effective.

If a panel installation includes bonding, the required structural adhesives should be line-itemed into the estimate for accurate compensation. If rivets are included with the panel, or purchased separately is another OEM specific consideration. Specially coated SPR’s specific to application are another consumable that should be added to the estimate.

Working with advanced structural materials has forced the collision repair industry to up our game another notch. This is the question we must ask: Is this a barrier, or an opportunity? Not wrong, just different, right? No doubt, these technologies require shops to tool-up and update technician and estimator training and expertise, require vehicle manufacturer’s repair information, and OEM specific equipment. The investment in time and money will minimize frustration in dealing with new technology, allowing for a return on investment through proper repairs, lowered liability, and a repaired vehicle that surpasses our customer’s expectations.

The technology is already being used. Valid, accurate estimating turns into a seamless repair plan. Intelligent estimates result in reduced cycle time, less shop anxiety, improved insurance KPI numbers, and satisfied customers to provide excellent CSI numbers and witness a repair that’s truly professional.

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