Straightened a chassis yesterday

[CarlG]

It doesn't take much of anything to start an arguement (ie: difference of opinion expressed very loudly) around here!

[ericr]

Brent nowhere do the Service Bulletins address frame straightening, but only parts like the front axle.

on the other hand there are remarks in the service literature about straightening the spokes in the wheels, which I think is a process that you have previously disapproved of.

[zzlegend]

Originally Posted by stouchton

Sorry guys - was just trying to find a friendly way not to start an argument

Well now. I hope you are happy. LOL.

[RonC]

Here's some information from the collision industry that explains that heat can be used to bend some structural steels such as Model A frames. It's interesting to note over heating (greater than 1200 degrees) will damage the metal properties.

http://www.i-car.com/pdf/fordfram.pdf

http://www.i-car.com/html_pages/tech...ml#Anchor-3800

http://genuinegmparts.com/pdf/techIn...ity_Matrix.pdf

[Cool Hand Lurker]

If you heat the frame beyond the "straw" color like on Brent's frame and then cool it with water, will the steel be hardened, crystallized, more brittle, etc. so that the frame could crack in that spot?

[BRENT in 10-uh-C]

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Originally Posted by Cool Hand Lurker

If you heat the frame beyond the "straw" color like on Brent's frame and then cool it with water, will the steel be hardened, crystallized, more brittle, etc. so that the frame could crack in that spot?

No, low carbon steel does not harden like as in "heat treating".

[JTW]

Brent, what color change is the steel frame achieving before you apply the wet rag, and how big an area are you doing on each heating? Thank you.

[BRENT in 10-uh-C]

Originally Posted by JTW

Brent, what color change is the steel frame achieving before you apply the wet rag, and how big an area are you doing on each heating? Thank you.

Generally it doesn't change color while the flame is on it, but after it has been quickly cooled by water. I guess I need to use an infra-red thermometer the next time we do it to know exactly but my guess is 400-500 degrees is hot enough. Ironically, we cure powder during powderpainting at 400° in our oven.

[ericr]

does anyone know why the part of the frame that always bends seems to be the driver's side? certainly the engine weight is relatively balanced between the two sides.

[Tom Wesenberg]

Originally Posted by ericr

does anyone know why the part of the frame that always bends seems to be the driver's side? certainly the engine weight is relatively balanced between the two sides.

The driver's weight and the battery weight would be a factor.

Engine torque would be pressing the passenger side down.

[Ross/Kzoo]

I'm just curious how much of a problem the bent chassis is with the "T". It sure starts out less rigid than the "A" frame.

[CarlG]

Check this out:

[BRENT in 10-uh-C]

Originally Posted by CarlG

Check this out:

OOooo, I had forgotten about that article. Kinda bad news IMO but it does help prove my point though. (They are recommending "over-stretching" the frame rail to compensate.) It also makes me shake my head at the 'stuff' they want you to use. Now let me see, where can I find two 10' sections of rail road track?? Oh, and now I need to find another bottle jack, and 4 long pieces of chain.


One thing that I will add from my experiences is that I don't think we always find they are bent more on the driver's side. Maybe it is coincidence?

[George Miller]

Originally Posted by ericr

does anyone know why the part of the frame that always bends seems to be the driver's side? certainly the engine weight is relatively balanced between the two sides.

I think drivers weight, battery, and steering gear when in the old roads hitting bumps with the wheels would put pressure on the frame. But who knows for sure. I will say out of the 25 A's I have owned most were bent on the driver side. I had one 30 town sedan with 85,000 that was not bent. I though it lived in town and was not on that many rough roads.

[Ross/Kzoo]

I have not thought about the steering gear. I can see why all the bumpy roads and shock to the steering components could transfer load to the frame.

[Tiny]

Does low carbon steel anneal?
My limited metallurgy knowledge tells me that heating it enough to soften it enough to bend would. How does one put the strength back in the steel after this process?

[BRENT in 10-uh-C]

Originally Posted by Ross/Kzoo

I have not thought about the steering gear. I can see why all the bumpy roads and shock to the steering components could transfer load to the frame.

I am not following. Exactly what or where would the loads be transferred to? I would think any heavy hit would affect the radius (wishbone) ball that is attached to the clutch housing and not the drag link. The steering sector housing when bolted to the frame would more than brace the area in the frame compromised by the hole for the sector shaft, wouldn't it? If anything, there should be a slight amount of triangulated bracing as the steering column is attached to the gas tank thus making that side a tad more rigid. Also, wouldn't most bumps and obstacles on the road be on the passenger side as they would be positioned more to the side of the road (curbs, gutters, washouts, etc.)?

[Tinbasher]

Glad to see you guys have learn't the first lesson about body and frame repair. Give one job to six different tech's and they all will do the job. Maybe six different ways but they will get it done. Good, bad or whatever!! I've learn't this after 20 years of teaching and doing this trade. And yes I understand metal and how it works. I wrote a book on it!!! And I've had great discussions on mild steel and if it can be damaged or hardened with heat and cooling. Does it change,doesn't change? All I know is that by heat shrinking the metal it becomes harder to hammer because the molecules become locked up or shrunk!!

My two cents worth: The Old Tinbasher.

[Ross/Kzoo]

Brent, my theory is that any pothole or quick driving movement against an obstruction could transfer to the pitman arm and then twist the steering box.

[ericr]

Originally Posted by Tinbasher

Glad to see you guys have learn't the first lesson about body and frame repair. Give one job to six different tech's and they all will do the job. Maybe six different ways but they will get it done. Good, bad or whatever!! I've learn't this after 20 years of teaching and doing this trade. And yes I understand metal and how it works. I wrote a book on it!!! And I've had great discussions on mild steel and if it can be damaged or hardened with heat and cooling. Does it change,doesn't change? All I know is that by heat shrinking the metal it becomes harder to hammer because the molecules become locked up or shrunk!!

My two cents worth: The Old Tinbasher.

I'm a little confused, are you in favor of heating or otherwise, thanks.