Bent Frames/chassis

Shocks, Springs, Brakes, Frame, Body Work, etc

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Mummert
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Bent Frames/chassis

Post by Mummert »

Is it just me, or has anyone else noticed high amount of vehicles especially trucks going down the road with bent frame these days. Are body shops doing that bad of work or are people picking the worst options they can get?
Its bad enough, that I feel like making a sign that says "your frame is bent" that I can hold up as I drive by.
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frnkeore
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Re: Bent Frames/chassis

Post by frnkeore »

Geoff, what makes you think the frame is bent?
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Mummert
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Re: Bent Frames/chassis

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When you drive behind them the rear wheels are not following the fronts. Dog tracking is what most people refer to it as. You can sight down the body and see the doors on one side of the car, and then you veer to the other side and you all see is the rear corner.
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Re: Bent Frames/chassis

Post by BCjohnny »

'Crabbing' can have many causes, not just bent rails ....... common one being not having the rear axle square on the perches
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Re: Bent Frames/chassis

Post by frnkeore »

There are locating pins, on the leaf springs, that go into the holes on the mounting pads, of the axles. They can shear and cause that. It happened to my 65 1/2 K-code Mustang. It's a quick fix but, driving it, you can't usually tell. The steering wheel, will give you a clue though.

If you know about about it, you can tell. I didn't know, I had Stock Car tires on 10" wheels, on that car, I drove from Orange to Oceanside, one time and the tires were hot and graining. Shortly after that, my wife was behind me and said the car was running crooked. I took it to a alignment shop and that's how I found out about it.
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Re: Bent Frames/chassis

Post by Chris_Hamilton »

Mummert wrote: Fri May 13, 2022 1:18 am Is it just me, or has anyone else noticed high amount of vehicles especially trucks going down the road with bent frame these days. Are body shops doing that bad of work or are people picking the worst options they can get?
Its bad enough, that I feel like making a sign that says "your frame is bent" that I can hold up as I drive by.
Me being a long time Body guy I know exactly what you are saying. 90% of the Techs can't pull frames correctly. They have no training or experience in doing so. I was lucky to have learned under several old guys many years ago who taught me how to pull a frame correctly using nothing more than a tram gauge. The biggest mistake guys make when trying to pull a frame is first not checking for diamond and not fixing the diamond condition before doing anything else.All frames will diamond to one extent or the other in a hard collision. Diamond is when one rail goes back (or forward in a rear hit) more than the other rail. Going from a rectangle shape to a diamond shape. It's what causes a truck to have that "dog track" look.
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Tom68
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Re: Bent Frames/chassis

Post by Tom68 »

Not just these days.

Down here in the land of Oz our 1976 Holden one tonners needed the diff shifted to true tracking. The problem is actually the front leaf spring mount being out.
The shackles are even on different angles side to side.

My quick rough fix.
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Re: Bent Frames/chassis

Post by dannobee »

We use something like this in circle track racing when the rules require leaf springs. But yes, I've noticed "dog tracking" cars and trucks have become more frequent of late. I've even noticed big rig trailers doing it.
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Re: Bent Frames/chassis

Post by lefty o »

ford econoline vans have been the worst dogtrackers for decades. they come like that right from the factory.
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Re: Bent Frames/chassis

Post by Racer71 »

Ford trucks, 250-350 have a wider front track from factory that makes them appear that way
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