The body repair manual on the vehicle maker web pages is the best source for answering this question. Sometimes, however, there are no recommendations from the vehicle maker. In this instance, it is a business decision between the insurer, vehicle owner, and repairer as to how the vehicle should be repaired.
Please note that Chrysler has stated that their parts should not be sectioned unless there is a:
- written procedure from Chrysler.
- specific part distributed by Chrysler (Mopar) as a partial component rather than a complete stamping.
This statement can be found in Chrysler's Unibody Analysis And Repair Fundamentals publication #81-699-6017.
Please note that Ford states that their parts should not be sectioned unless there is a written procedure from Ford.
Please note that Honda has the following statement regarding sectioning of their parts:
Repair at factory seams with the same procedures as the factory assembly process except where specified otherwise in Honda and Acura Body Repair Manuals (rear frame rails, rear floor) or the replacement part is sold as a section (quarter panel, rocker panel, or outer side panel). The quarter panel is considered to be a structural panel.
The Partial Replacement Recommendations Matrix can be helpful for determining if sectioning procedures exist for a vehicle. The matrix identifies OEM-approved partial replacement recommendations for the following general areas:
- front lower rail
- pillars, rocker panel, and roof rails
- rear rail
- trunk floor
2. When should a structural part be repaired vs. replaced?
Deciding whether to repair or replace a structural part may be determined by whether a part is kinked or bent.
A bend is defined as a change in shape of the part between the damaged and undamaged area that is smooth and continuous. When the part is straightened, it is returned to proper shape without any areas of permanent deformation.
A kink is defined as a sharp bend with a small radius, usually more than 90° over a short distance.
A part is also considered kinked if, after straightening, there is a permanent area of deformation that will not return to its pre-accident shape without the use of excessive heat.
Kinked parts are typically replaced because there are changes in the metal structure. These changes create permanent damage that cannot be repaired regardless of the type of repair performed.
Additional considerations to the kink vs. bend rule include:
- extent of damage.
- location of the damage.
- if the area is subject to repeated stress.
- type of surface (e.g. flat, corner, or engineered shape).
- restoration of the corrosion protection.
- restoration of part dimensions.
In some instances, bent parts cannot be straightened either due to the strength of the bent part or the vehicle maker recommendations. For example, on Ford full frame vehicles, straightening bends in the crush zone of the front frame horn is not allowed.
Consider attending the following I-CAR training program for more information on kink vs. bend:
3. Can a full frame be sectioned?
The body repair manual on the vehicle maker web pages is the best source for answering this question. In some instances, however, there is no recommendation from the vehicle maker. Therefore, it is a business decision between the insurer, vehicle owner, and repairer as to how the vehicle should be repaired. General sectioning guidelines may assist in this decision.
Please note that Chrysler has stated that their parts should not be sectioned unless there is a:
- written procedure from Chrysler.
- specific part distributed by Chrysler (Mopar) as a partial component rather than a complete stamping.
This is stated in the Unibody Analysis And Repair Fundamentals publication (#81-699-6017).
Toyota has also stated that they do not want their full frames sectioned. This is stated in Toyota's Structural Repair Precautions - (CRIB) #89.
Please note that Honda has the following statement regarding sectioning of their parts:
Repair at factory seams with the same procedures as the factory assembly process except where specified otherwise in Honda and Acura Body Repair Manuals (rear frame rails, rear floor) or the replacement part is sold as a section (quarter panel, rocker panel, or outer side panel). The quarter panel is considered to be a structural panel.
For more information on which full frame vehicles have sectioning procedures, refer to this I-CAR online Advantage article: A COMPREHENSIVE GUIDE TO FULL FRAME SECTIONING
Consider attending the following I-CAR training program for more information on sectioning full frames:
4. Can a tear or crack in the frame rail be welded or does the part have to be replaced?
Crack repair is generally a business decision as most vehicle makers provide limited information regarding this type of repair. Ford, however, provides the following information regarding repair of frame rail cracks:
Ford's Recommendations:
Ford recommends that cracks resulting from repairs can be welded and then should be reinforced by installing a piece of the same material and thickness that extends 100–150 mm (4–6") beyond either side of the crack and is welded completely around its perimeter. There are four restrictions regarding the repair of Ford frame cracks:
- Cracks cannot be repaired within the crush initiator area.
- Cracks caused by repairing a kink cannot be repaired.
- Cracks located in the area of the steering gear cannot be repaired.
- Cracks located on the flange area of a C-channel frame should not be repaired.
Generally, frame cracks that should not be repaired include those:
- near the steering box area.
- near a suspension mounting area.
- on the top or bottom flange on a frame with an open C-channel design.
- caused by straightening an area that was previously kinked.
Consider attending the following I-CAR training program for more information on repairing cracks in full frames:
5. What are the I-CAR recommendations regarding the:
- amount of time allotted to a repair?
- use of specific products?
I-CAR has a very specific and strict policy about addressing issues that may affect anti-trust laws. Therefore, I-CAR will never address:
- how much time should be allotted to a repair.
- what is or is not an included operation.
- which repair operations should be performed by a specific department.
Additionally, I-CAR uses a variety of products, equipment, and makes of vehicles in photos and videos that appear in the I-CAR training materials. I-CAR may offer specifications or recommendations of types of equipment and/or products that will deliver the required performance for collision repairs. However, I-CAR does not recommend, endorse, or approve specific brands of products to the collision industry.
Consider attending the following I-CAR training program for more information on writing vehicle damage estimates:
6. What must be replaced following an airbag deployment?
On the I-CAR web site, under the "About I-CAR" pull-down menu on the main page, there is a link to the "Airbag Parts Replacement Chart." This portion of the web site is devoted to listing:
- vehicle-specific parts replacement recommendations.
- parts that must be inspected and replaced if damaged.
- disable procedures and wait times.
The airbag chart may also be found at the following link: I-CAR Airbag Replacement Charts Search
Consider attending the following I-CAR training programs for more information on supplemental restraint system repair:
7. What are high-strength steel heating recommendations for each vehicle maker?
Heat tends to strengthen mild steels, weaken high-strength steel, and
completely destroy the strength of most ultra-high-strength steels. For this
reason, use cold straightening during collision repair unless steel
identification and heating guidelines are available from the vehicle maker.
Unless vehicle maker recommendations state otherwise, using heat for stress
relieving HSS and UHSS parts should only be done when the parts are going to
be replaced.
Some vehicle makers have specific recommendations for the use of heat. An
example is the Recommended GM Steel Reparability matrix at the free GM web
site: goodwrench.com/gmgoodwrenchjsp/gmspo/index.jsp
From the top of the home page, select the Tech Info link. Then select the
Steel Reparability Matrix file from the list on the Technical Information
Page.
Consider attending the following I-CAR training program for more information on heating and straightening high-strength steel:
Structural Straightening Steel (SSS01)
8. What is the I-CAR recommendation regarding the use of recycled parts (including airbags)?
I-CAR does not have a position on the use of recycled or aftermarket parts. However, if an aftermarket or recycled part is being installed, there are specific criteria that must be met before installation. For example, do not install a recycled part that has:
- unrepairable damage.
- corrosion that has caused pitting.
- improper previous repairs.
- missing mounting locations.
When installing a recycled part, prepare the part by:
- cleaning the part to remove dirt, wax, grease, undercoatings, corrosion, etc.
- removing all heat-affected zones.
- making sure it is trimmed properly to fit.
- making sure the part is not deformed along the weld joints.
Recycled airbags should not be used. Without knowing the condition of the vehicle, it is difficult to know if the airbag functioned properly during the last collision. It is also difficult to know if the airbag has been previously repaired. Therefore, using recycled airbags may pose an unnecessary liability risk.
9. What is the I-CAR recommendation regarding the use of adhesives for panel installation?
I-CAR recommends following the vehicle maker's recommendations regarding the use of adhesives for panel installation. Using adhesives without the vehicle maker's recommendation is a business decision.
With that being said, there has been an increase in use of adhesives by the vehicle makers. General Motors has begun allowing the use of adhesive on several outer body panels. In General Motors technical service bulletin #02-08-98-001, GM provides specific recommendations regarding the use of adhesive on roof panels, door skins, quarter panels, and rear body panels on specific vehicles. Using adhesives on GM vehicles without specific procedures is a business decision.
Weld-bonding is also another method of panel replacement that may be recommended by the vehicle maker. Weld-bonding is the combination of using STRSW or GMA (MIG) plug welds along with adhesive to attach an exterior body panel.
When weld-bonding, DaimlerChryler recommends "to replace any suspected adhesive with a two-component, corrosion inhibiting, epoxy structural adhesive when any repairs are made, providing the STRSW process is applicable. The adhesive must meet or exceed Chrysler MS CD507."
Vehicle makers that have specific recommendations against the use of adhesives on their vehicles include:
Honda/Acura recommends to “repair at factory seams with the same procedure as the factory assembly process except where specified otherwise in the Honda And Acura Body Repair Manuals. Please note that the door skin is welded at the top of the skin, and is glued around the crimp.”
As previously mentioned, using adhesives on any vehicle not discussed in this section is a business decision. It is important to note, however, that almost all vehicle makers allow the use of adhesive for installing door skins.
Consider attending the following I-CAR training program for more information on using adhesives:
10. How are plastic parts identified and what should be used to weld or adhere them?
When determining the identification of a plastic part:
- the level of identification depends on the repair method. For welding, it helps to know the specific type of plastic to determine which welding rod to use. When using adhesives and fillers, the level of identification that is necessary is determined by the product maker.
- the identification test is determined by the product maker. These tests include determining whether the plastic is a polyolefin and the flexibility of the part.
- consider the refinish material recommendations. The refinish material may require a flex additive in one or more coatings, or an adhesion promoter for undercoats.
The best way to identify a plastic part is to use the International Organization for Standardization (ISO) code. ISO codes are a standard set of letter codes that identifies the plastic or the manufacturing process. Whether ISO codes are identified on a part is not consistent among automotive plastic suppliers.
Some parts have a combination ISO code that identifies a commercial blend of plastics. An example is PA + PE, which is a combination of polyamide (PA) and polyethylene (PE).
To locate the ISO code on a plastic part, the:
- code may be molded into the backside or a non-visible area.
- location is not consistent from vehicle-to-vehicle or part-to-part.
- part may have to be removed.
Plastic identification and repair information from the OEM:
- is located in body repair manuals, service manuals, or plastic repair manuals.
- includes exterior parts.
- includes interior parts.
- does not show a mid-year change in the type of plastic that is used.
After the ISO code has been used to identify the plastic, the plastic repair material maker may put it into a flexibility classification that defines the repair material that should be used in their system.
Consider attending the following I-CAR training programs for more information on repairing plastics:
