How to measure/identify bent chassis or beam?

[bnam]

A friend’s car had for a long time had an sig towards one side and badly rotted heater channels and pans. So he had a shop do the restoration. But the pan and body work was outsourced to a second shop. With the body off, it was noticed that the frame head had been damaged and repaired and broken again. So new frame head was installed along with new pans and heater channels.

The pan and body were sent back to first shop where upon assembly it was noticed that the car sagged to the front right. Rear suspension had been properly reset, so that was not a contributor. The guy who did the pans and frame head insists the pans and head are straight but the beam could be bent.

Without access to a proper frame repairing setup, I was wondering how we could figure out where the problem lay. This is what I am considering:

Set up 2 jack stands equally spaced from the mid point under the rear torsion bar. Before setting the car on these stands, we’d put a square tube on top of the stands and put a level on it to make sure the top of the stands were level. We’d shim the stands as needed.

A third stand would be set up to be under the middle of the tunnel, just aft of the napoleon hat. We’d shim this third stand so that a level placed on top of the tunnel in the car would show that it was horizontal.

My thought is that this gives us a level base against which to take measurements.

We’d then lay two more square tubes under the car. One directly under the napoleon hat, and another under the beam. Both would be shimmed to make sure they are horizontal from left to right.

Now if we measured between the ends of the napoleon hat to the reference tube lying beneath on the floor, the difference in left and right measurements should reveal any twist there. Similarly, comparisons of measurements at the ends of the beam and below the points where the beam mounts to frame head should reveal any differences.

Would this work? Any other tips?

Thx,
Byas
_________________
1971 1302LS Convertible (RHD) owned since '74
Click to view image
1965 Karmann Ghia Coupe - under restoration
1966 Fiat 1500 Cabrio (with 1600 Twin cam)
1952 Citroen TA 11BL

[Bobs67vwagen]

This sounds like it would work to me. Collision shops use a similar system with hanging rods to determine what areas need work. The difference is that they use precise measurements in the manuals that spell out what the measurements should be from specified hole to specified hole and some use lasers with this method. I think you could also add in precise measurement from front axle center point to rear axle center point with the front steering in the straight ahead position and compare from each side and see how they compare.