Is this a sagging frame issue?

[billybronco1]

When I hear people talk about a sagging frame or say the frame is straight I always wonder what they are referring to with regards to a Model A. When I think of a car with a non straight frame I think of a car that has been in a bad crash. Does this picture depict a sagging frame issue on this car? I see this a lot on Model A's but this is very prominent on this one with a big gap at the bottom of the hood and tight at the top against the cowl.

[QGolden]

It matches other sagging frame pictures I have seen. Worst than a lot of them.

[Tim Armstrong]

That's what I had on my 30 model. I used a 4 inch square tubing and placed it under the car. I chained the back of the frame to it and removed the front fender and chained the front of the frame to it. Placed a 10 ton hydraulic jack under the frame cross member. Slowly jack up one side until the sag goes away and the hood fits. Repeat on the other side, Works great. Poor man has poor ways but I got the results I wanted.

[Bruce_MO]

I had a frame that I had to throw away after cutting out the crossmembers. It had a pronounced "kink" at the motor mounts, which caused the hood alignment problem shown in the photo. When I removed the motor mounts, it was obvious why... the rails were very deeply pitted over almost the entire inner and outer surface of the rails and the bolt holes for the mounts were 2X their normal diameter. Before trying to straighten a bent frame with the body still on the car, it might be worthwhile to at least remove the outside motor mount plates to see what the condition of the frame rail is in that critical area.

[BRENT in 10-uh-C]

When straightening a frame, use heat to return the metal back to the original shape and not force simply because the metal is already stretched. Using force only stretches it in another place and only rearranges the metal thus making it vulnerable to re-bending.

[ericr]

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Originally Posted by BRENT in 10-uh-C

When straightening a frame, use heat to return the metal back to the original shape and not force simply because the metal is already stretched. Using force only stretches it in another place and only rearranges the metal thus making it vulnerable to re-bending.

Brent this might have been asked and answered a billion times but.....how does this comport with the repeated statements in the Service Bulletins and elsewhere to straighten bent parts cold?

[BRENT in 10-uh-C]

Originally Posted by ericr

Brent this might have been asked and answered a billion times but.....how does this comport with the repeated statements in the Service Bulletins and elsewhere to straighten bent parts cold?

It has been asked here "a billion times". My answer always is the same.

.

[ericr]

Originally Posted by BRENT in 10-uh-C

It has been asked here "a billion times". My answer always is the same.

.

-and that answer, for the one billionth and one times, is......?

[Ron in Quincy]

Answering the question to the original post, it is common after a number of years for the frame to have sagged at the rear motor mounts, usually more on the driver side if the A has been driven at lot with just a driver.

Over the years I have straightened a number of frames, cold, no heat, and have not had a problem with the frame later taking a sag.

The sag condition becomes very evident when the hood gaps at the bottom rear cowl end and over laps the radiator shell at the front bottom.

If going to restore an A, remove the body, check the frame, correct any problems found like cracks and sags. Its better to not wait until the body is all painted and find the hood does not fit correct because the cowl is low.

Just my opinion,

Ron

[1931 flamingo]

ericr: What he said : "When straightening a frame, use heat to return the metal back to the original shape and not force simply because the metal is already stretched. Using force only stretches it in another place and only rearranges the metal thus making it vulnerable to re-bending. "

Paul in CT

[a-bone newby]

they straighten bridges with heat so it cant be all bad

[Mike V. Florida]

Will bending the frame cold "work"? Yea it will make the part straight but it will also stretch it, making it longer. Is that a problem? Maybe, maybe not.

Any bend/dent in metal is a result of a stretch. Think of one of those bendy straws, as you bend it one side get longer. Bend it the other way and the straw will get longer unless those little folds go back in place. Same with metal.

[ericr]

Originally Posted by Mike V. Florida

Will bending the frame cold "work"? Yea it will make the part straight but it will also stretch it, making it longer. Is that a problem? Maybe, maybe not.

Any bend/dent in metal is a result of a stretch. Think of one of those bendy straws, as you bend it one side get longer. Bend it the other way and the straw will get longer unless those little folds go back in place. Same with metal.

that is an understandable analogy and I might add IMO this piece of information is perhaps one of the most valuable yet counter-intuitive tidbits on the Barn.

[Terry, NJ]

In reading the above, I have not seen the word "Fatigue" where one would look for it! When we bend metal back and forth, it "fatigues" and weakens and eventually breaks. But not until it goes through several stages of weakening first. Heat helps with this. It's all in the molecules!
Terry