Automotive Terminology with Classic Toyota of Waukegan: The Chassis and Frame

Oct 13, 2023

It’s time for another helpful edition of Automotive Terminology Decoder! Each month we’re sharing some posts with helpful terms, vocabulary, and phrasing used by mechanics, service technicians, and industry professionals. It’s our hope that we can help arm you with the lingo and knowledge you need to navigate car ownership, car buying, and vehicle maintenance with ease. Have a suggestion for a future update? Let us know in the comments what terms and questions you have about automotive life.

The Chassis is, in short, the structural, load bearing frame of a vehicle without its body. It includes all of the major components including an engine, the transmission system, the gearbox, propeller shaft, the axles, control systems like the brakes and steering, and the suspension system.

Modern cars use a unibody construction, which means the frame and body skeleton are manufactured as one singular piece. The frame or unibody is the piece that everything else attaches to, so it must be the absolute strongest part of the vehicle. The suspension system includes the control arms, springs, struts, and shock absorbers. The steering gear helps control the vehicle’s direction. The transmission and drive shaft help control engine rotational force and manage speed. The engine provides the force which moves the vehicle from place to place and provides power. The engine is attached to the chassis with motor mounts; axle assemblies, wheel hubs, suspension shocks and springs, and other components are all mounted directly to the chassis.

When a vehicle is involved in a collision or accident, it can cause some serious frame damage. This is usually when insurance adjusters get involved, to help you assess the damage and extent of repairs required or if it is a total loss. Perhaps, however, you’ve been in a minor fender bender and chosen to avoid reporting to insurance, and have gone about your merry way until you noticed your car is not driving properly. Sometimes, we discover what seems like a minor incident initially, turns out to have caused greater damage than we realize. Here’s a few things to look over, and some ways that you can assess for signs of car frame damage so you know what to look out for.

Walk around your vehicle paying close attention to details, and inspect underneath it for any signs of frame damage or stress.
If you notice that doors, trunk/hood, and other parts of your vehicle don’t seem to be properly aligned nor close smoothly and securely, this may indicate body or frame damage.
Check all of your tires for wear and tear, and if they’re wearing unevenly, you may want to bring your vehicle in for an inspection with your local mechanic.
If you notice that your vehicle rear wheels don’t align with your front wheels when driving straight, and it’s veering a little to one side or the other, this may indicate the frame is bent.
If you’re noticing new and “exciting” noises such as rattles, clinks, clanks, rumbling, or whining that weren’t there before the incident occurred, it may signal frame damage.

Any one or all of these signs indicate that your vehicle is in need of repair and a trip to the body shop. It may be possible to repair the frame back to a pre-collision condition, saving you further costs of damage down the line. If your car insurance company has decided that the frame damage is too severe to fix, or the costs outweigh the value, you’ll want to forgo the repairs and take the assessment to heart, and follow the steps to claim your vehicle with your insurance company.