The undercarriage is an important part of any vehicle, and unlike the main body of the car, it can easily be overlooked by dealers in a trade-in. But this can work to your detriment, since it's the true foundation that keeps everything on a vehicle running smoothly and safe. In this blog, we’ll review what to look for when customers are trading in a vehicle to check for undercarriage damage, what causes it and how to fix it
What parts are in the undercarriage?
The undercarriage includes a complex set of systems in any vehicle that keep it functioning properly – and safe to drive. It includes the chassis frame that supports the car, the suspension system, exhaust system, brake lines, fuel lines, and drive train. This means it encompasses shocks, the muffler, catalytic converter, axels, and more. If any of these parts are functioning improperly, the vehicle functioning and therefore value will decrease, and you don’t want to get taken by surprise and accept a faulty trade-in.
Why do dealers often skip undercarriage checks?
In many situations, visible wear-and-tear like paint scratches and the condition of upholstery is taking the full focus, leading to the undercarriage getting overlooked. With tools like ClearCar you can spend less time looking for scratches and dents, because ClearCar AI damage detection tool can identify those scratches and dents with just a photo, giving you more time to spend on the undercarriage. After all, neglecting to conduct a full check is costly for dealers who wind up having to make expensive repairs in recon in order to sell the car, or risk losing their reputation from selling a faulty vehicle at retail.
Signs to look for with undercarriage damage
Undercarriage damage will be noticeable in several formats, including visually, through sound, and by way of the vehicle’s performance. Look for:
- Rust or corrosion
- Dents and scrapes that result from hitting the road
- Leaking fluids that can point to either the fuel or brake line
- Rattling noises that can result from loose parts
- Scraping sounds that point to low-hanging parts like the exhaust
- Unstable steering that pulls to one side
- Unevenly worn down tires
- A shaky driving experience
- Reduction in the efficiency of fuel
- Brake issues
What causes undercarriage damage?
Typically, undercarriage damage is a result of wear and tear over time, caused by how the owner has driven, the types of roads, and quality of those roads. Some common factors that can lead to deterioration include:
- Potholes, speedbumps, debris, or curbs that can knock or scrape parts of the undercarriage
- Salt, mud, water, rocks, or gravel that can accelerate rust and corrosion
- Aggressive driving that strains components
- Overloading the weight of the car which adds pressure
- Lack of maintenance which can speed up minor damage until it worsens
How to solve for undercarriage damage
Undercarriage damage can be resolved through minor repairs, for example surface rust can often be scrubbed off and loose pieces may be able to be replaced with new bolts. For more serious issues, welding, replacements, or realignment may be necessary depending on the severity and can help early signs from worsening.
How do you know when it’s too damaged to accept the trade-in?
While we’ve discussed some issues and common fixes, problems like corrosion of essential structural components can mean that the vehicle is beyond repair and it would be better to walk away from the potential trade-in or your offer to the customer needs to include these costs and it might be considered “too low” for a customer to sell their car . The cost of the repairs may outrun what the vehicle is worth, or worse yet, it may never be fully fixable and you’ll find yourself trying to sell a vehicle that is not safe to drive in. For example, if the vehicle is missing the Catalytic Converter, they typically range between $1,000 to $3,000 for replacements, which is a huge cost to take off of a trade into a customer3.
Use ClearCar to help you detect damaged trade-ins
At ClearCar, our AI damage detection tool allows dealers or customers to take exterior photos of their car using their phone. The images are then scanned by the AI tool to help the dealer detect damage. The photo will be tagged, calling out areas where there are dents and scratches. ClearCar’s AI tool leverages millions of data points from ACV marketplace data, inspections, and the ACV MAX inventory management system to put a solid number on what the car is worth. Our tool makes the trade-in process pain-free, accurate, and efficient. Try it today.
Sources
- Delrahim, Ash. 2025. “Undercarriage Damage On Your Car: Causes And Solutions.” Bliss Car Wash. Retrieved July 1, 2025. https://blisscarwash.com/undercarriage-damage-on-your-car-causes-and-solutions/
- CarStudio. 2025. “How to Spot Undercarriage Damage Before Buying a Car.” CarStudio. Retrieved July 1, 2025. https://carstudio.ai/how-to-spot-undercarriage-damage-before-buying-a-car/
- "Catalytic Converter Replacement Cost: What Affects the Price." Air Tasker, 26 May 2025, www.airtasker.com/us/costs/mechanic/catalytic-convertor-replacement-cost/#:~:text=Key%20Facts,and%20a%20check%20engine%20light. Accessed 7 Jul. 2025.
