Frame cracking away from torque box

I don’t know how I missed this. I had her up on wheel skates while the seats were at the upholsterer, and while underneath reinstalling the passenger seat I happened to look forward and spotted this:



I don’t see any other damage around it, and the driver side box is solid. I know virtually nothing about framework, so is this a common break or indicative of a collision? The odd thing I did notice right away is that nothing fits quite right on the driver side, and I know it has at least a fender that isn’t original. Otherwise, there aren’t signs of major damage anywhere. There’s some putty in the quarters, but no signs the panels crinkled or were significantly impacted. I think the passenger fender is original, as are the hood and decklid.

It’s hard to say why the weld is broken. I would recommend taking it to a good body shop and have them measure the frame for being true. If so have them(or somebody) weld it up. If not have the frame pulled first them welded up. If the car drive well you could get by with just having it welded. But I don’t recommend that.

This is the same area on a 70 Cougar I am putting new floors in to.

Thanks for the insight. Our local club chapter meeting is on the 19th, so I will solicit opinions on a Dallas area shop that can be trusted with vintage frames. I went back to the photos taken in December before I brought the car home, and found this, which in a way makes me feel better. I knew I’d checked it, so this cracking problem is new.



A commom place to look is at the floor pan from under the car, look for ripples in the pan or holes that are stamped in the unit body that should be round that are not.

I dont think this isca paralax…but …it looks like the risers on the floor pan …go underneath the floor extensions and the floorpan appears to be welded to the support at the peaks of the risers ? This means that pan is shifted inboard ? Which makes me consider the car suspect to a crime of improper repair. The floorpan althougj not a heavy gauge sheetmetal …should be FLAT on thr floor extension and properly welded to the inner rocker. I posted a picture of how that pan should sit

I think his is sitting the same way.

I would just have Mid Cities Mustang remove the torque box and install a new one correctly. They have a frame alignment jig and know how to use it.

https://www.midcitiesmustang.com/services/restoration/

Thanks for the referral, Royce. I’ll give them a call. Some prior owner added subframe connectors that I wanted to have looked at already, so they just jumped line on the to-do list.