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Summary
  • Frame damage refers to any damage that affects a vehicle’s chassis. This is typically brought about by disrepair or collisions.
  • There are three types of car frame damage: twisted frames, mash damage, and sway damage.
  • Common symptoms associated with frame damage include unusual tire wear, gaps in the body panel or misalignment, and an uneven suspension system.

If you’re ever in a serious automobile accident, frame damage is one of the first concerns you should have your mechanic check. But what is vehicle frame damage, and what makes it so difficult to repair?

What Is Frame Damage on a Car?

Frame damage typically refers to any damage that affects a vehicle’s chassis. Disrepair or collisions can cause frame damage. A damaged chassis is often hazardous and can make a vehicle unsafe to drive especially if the damage heavily affects the vehicle’s structural integrity.

Minor frame damage or damage that doesn’t directly impact the vehicle’s structural support includes paint scratches and smaller dents. Major frame damage impacts the vehicle’s main structural support. Crumpled panels and bent beams are examples of major frame damage.

damaged frame of a car
The three types of car frame damage are twisted frame, sway damage, and mash damage.

Types of Car Frames

To properly understand car frame damage, we need to look at the types of car frames. The car frame, also known as the vehicle’s chassis, is typically made of steel or aluminum. Exceptions would be on unibody vehicles where the frame is actually part of the car body. This is a lot more common on front-wheel-drive vehicles than on rear-wheel-drive vehicles. We’ll discuss this under the “Unibody” section later in the article.

The frame is designed to support the vehicle’s mechanical components and the vehicle’s weight, retain the vehicle’s shape, and also protect everything inside the vehicle in case of a collision.

Collisions affect these frames differently, and as a result, the damage to the frames tends to differ as well. While there are many types of car frames out there, most vehicles on the market have frames that fall into two main categories: body-on-frame and unibody.

Body-on-Frame

The body-on-frame design consists of a body attached to a structural frame that carries both the suspension and the powertrain. It’s literally the vehicle’s body on top of a frame. The two parts aren’t merged together. Rather, the body is often bolted onto the frame. Common body-on-frame designs are the ladder frame, the backbone chassis, and the platform frame.

Body-on-frame designs withstand rather than absorb the impact from collisions, making them much more resilient to frame damage. A lot of force is needed to bend the sturdy construction of body-on-frame vehicles.

Unibody

Unibody frames are also somewhat self-explanatory. The name is a shortened form of “unit body” or “unitized body.” The vehicle’s body, its floorboards, and all major elements for chassis structural support and crash-protection are joined into a single cohesive structure. The frame and the body are attached, and the two support the vehicle as one.

Despite being more complex and difficult to build, unibody frames are much lighter. They’re designed to crumple and absorb the force from a crash, softening the blow for any of the vehicle’s occupants. This makes frame damage more likely in the event of a crash, but it’s all in the name of safety. Most modern passenger cars have a unibody design. SUVs typically have a more old-fashioned ladder type frame with crossmembers.

Types of Car Frame Damage

The three types of car frame damage are twisted frame, sway damage, and mash damage.

, A Comprehensive Rundown on Car Frame Damage

Pro Tips are nuggets of information direct from ASE-certified automobile technicians working with CarParts.com, which may include unique, personal insights based on their years of experience working in the automotive industry. These can help you make more informed decisions about your car.

Pro Tip: Well-equipped body shops will have frame-straightening machines to bring damaged frames back into spec.

Twisted Frame

A twisted frame is difficult to spot. If a vehicle has a twisted frame, you’ll likely notice it leans in odd directions, has body panel gaps, and shows uneven tire wear.

Mash Damage

Mash damage is usually the result of a head-on or rear-end collision compressing the frame like an accordion, leading to the frame being shorter than it used to be. It can occur even at low-speed collisions.

Sway Damage

Sway damage is the result of a car getting hit in the corner or t-boned. The frame bends either to the left or right, making driving the vehicle in a straight line a struggle. Sway damage also leads to odd vibrations while driving and driveshaft issues.

Symptoms of Frame Damage on a Car

It’s important to have your vehicle assessed after any accident. A mechanic will be able to read the signs of car frame damage much better than anyone else. That being said, you might be able to notice a few of these symptoms yourself:

Body Panel Gaps and Misalignment

Uneven gaps and misalignment can keep the doors, trunk lid, and other body panels from lining up properly. You might even notice the fenders either sinking into the body or bulging out. These may indicate frame damage.

Unusual Tire Wear

Frame misalignment can cause uneven tire wear, which in turn can affect your vehicle’s handling. Check if your tire’s tread pattern is wearing out unevenly.

Uneven Suspension

If your vehicle appears off-kilter, with one side or corner drooping more than the others, it may be a sign of frame damage.

Visible Damage

You might be able to see the damage to your vehicle’s frame outright. Dents, bends, and creases in the frame structure are indicators of frame damage. Damage to the frame might also affect the undercarriage, so getting under the car might be necessary to spot any kinks in the frame there.

Steering Problems

Steering problems, such as the vehicle leaning to one side, can stem from frame damage affecting wheel alignment. Driving in a straight line can be difficult in this scenario.

Unusual Shaking

Your vehicle’s frame is meant to distribute the vehicle’s weight evenly as you drive along. If the frame is compromised, then you might experience unusual shaking or a more bumpy ride than usual.

Problematic Handling

A damaged frame can negatively affect your vehicle’s handling. This can be dangerous especially at high speeds. You may feel looseness in the steering, which can make it hard to keep control of the vehicle.

Concerning Sounds

A number of different sounds might point to frame damage. This includes rattling sounds under the vehicle, humming or whirring from the tires, grinding or scraping when taking turns or going over bumps, and creaking or groaning noises emanating from the suspension or chassis. You might even hear knocking sounds when you swerve or drive over rough roads.

Is it Worth Repairing A Frame-Damaged Car?

A well-equipped auto body shop should be able to fix the frame of your vehicle without a problem. The question is “is it worth it?” The answer depends on the extent of the damage, the cost of repairs, and the insurance coverage. If the extent of the frame damage is a small dent that poses no problems for structural stability, then a repair is definitely worth it. It’s another matter if the damage is major.

Many insurance companies might determine that the cost of repairs outweighs the value of your vehicle, and you’d need to register for a rebuilt title to legally drive it again. In that case, it might be worth scrapping the vehicle and buying a different one.

Whichever the case, if you suspect your vehicle is experiencing frame damage, make sure to have it assessed by a professional, especially after any accidents. What appears as minor frame damage might be more serious than you can determine, and it’s always better to be safe than sorry.

About The Authors
Written By Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

File Under : Car Body , DIY
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