Inspecting chassis rails

[RichyRich]

Hey, just thinking, have a rolling shell I’m interested in purchasing, but wondering how one might check it for structural rust, especially the chassis rails. Crawl underneath and tap with a hammer? Poke at suspect spots with a screw driver? (Assuming the seller lets you).

Do the rails rust from the inside (not sure how water gets in) or from the outside? 

What / where else would you check a shell, apart from visibly obvious? Datum measurements, maybe, or is that a bit unrealistic. 

Don’t want to spend $10, $15k on a shell then find in first two weeks of owning it’s only good for panels and off cuts.

Cheers, Richard 

 

[AndBir]

On 12/28/2025 at 5:30 PM, RichyRich said:

wondering how one might check it for structural rust,

Hire or buy a borescope inspection camera to look at the inside surfaces of the shell / rails etc.

[Williams Hortons]

Get it on a hoist or stands and inspect with a torch. Lightly tap and probe any suspect rust areas to check for soft metal, as rails can rust inside and out. Pay close attention to suspension mounts, sills and floor pans. For that kind of money, a professional inspection is worth it.