It’s required to raise and support the vehicle with tools like jack stands to do a lot of repairs. Before raising and supporting the vehicle and working on it, it’s important to inspect the frame and confirm it’s safe to work under. Find out how to inspect the condition of your car or truck frame as we demonstrate these steps on a rusted car frame that is unsafe to work under.
How to Inspect a Rusted Car or Truck Frame
Signs the Car Frame Is Rusted and in Poor Condition
Some of these symptoms alone do not mean the frame is in poor condition, but a number of the following signs are strong indicators
- Cracks
- Soft spots
- Disconnected or corroded brackets
- Easily bendable metal
- Stress cracking
- Rotted holes
Mechanic’s Tip: If the frame is riddled with these symptoms in some areas and not in others, the frame can still be unsafe to work under. Even lifting a vehicle with a weak frame from its strong points can place more strain on soft spots, creating more risk for cracking and breaking.
How to Check a Rusted Car Frame
Steps for Inspecting a Rusted Car Frame
- Complete a Visual Inspection
Inspect the frame for surface rust. Surface rust does not always mean there is an issue with the frame if it is sturdy enough. Watch this video for more information about inspecting surface rust.
- Check for Missing or Weak Parts of the Frame
Look for missing parts of the frame, like the missing upper section from the C channel in the picture below. Missing pieces and sections that are weak and can be easily bended are signs of a frame in bad condition.
- Tap the Frame with a Hammer to Test Sturdiness
If you come across a part of the frame that looks soft but you are unsure of its sturdiness, try tapping it with a hammer. A frame weak enough to tap holes through is soft enough to fail.
If you tap the hammer and the frame remains firm, it is a sign of a frame in good condition. - Look for Loose, Torn, or Corroded Brackets
Look for torn and loose brackets that are not longer able to bolt to the frame and are too corroded to be stable.
- Check Both Sides of the Frame Thoroughly
Inspect both sides of the frame thoroughly. A frame fine on one side but not on the other can still strain the soft side when lifted.
- Look for Stress Cracking
Check for stress cracking, which is a very bad sign. Stress cracking is worse than tapping holes into soft spots, because it is a sign there was enough stress to break the frame. Reinforcing the crack like in the picture below only sends the stress to other parts of the frame.
- Check for Holes in the Frame
Holes in the frame are also a sign of a frame in weak condition
Not all of these signs indicate there is a problem with the frame, but at the least they indicate that the frame is beginning to wear. If multiple parts of the frame are in bad condition and unstable, it’s safe to say the frame is unsafe to work under.
Jack Up Your Vehicle with 1A Auto’s How-to Videos
Learn how and where to jack up your own vehicle with 1A Auto’s how-to videos that will explain what places are safe to jack up from and support. Find out how to do other diagnostics and repairs with instructions and advice from real mechanics for many makes and models.
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