Boxing the Frame

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JrSyko

Jerry Maguire
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My cousin has a Bronco and was thinking about boxing in the frame. He doesn't beat on it too hard, never going to race it, but plans on having it for a long time. Stupid question of the week: can you box in just parts of the frame, and if so what sections do you recommend? Or, should he just leave it the way it is? Thanks guys.
 

mcne

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I have only seen entire frames boxed. Never just partial frame. Good question.
 

blind655

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I would think you should box the whole frame or none at all. If you were to box only a portion of the frame wouldn't that cause stress to be put on to the parts of the frame that are not boxed and cause them to fail? Just an idea..
later
Mike
 

SpareChangeRacng

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I would think that boxing certain areas would make only those areas rigid, allowing the non boxed areas to flex still. Put the 2 together and it's a bad scene = cracks in the frame. I'd say leave it, or box it all.
Think of it like a cage - you don't want t have bushing mounts and solid mounts on the same cage, or 1/2 rigid and 1/2 flexible. The bushing mounts allow for flex, and the solid mounts do not - not a good combo. Steve
 

michael_loomis

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look at the frame , some sections are boxed from the factory and some arent .... atleast my sonono is like that , and so is my fiancee's 01 silverado . they want the frame to flex somewhat , otherwise ride qualty gets stiffer , and that leads to other problems like rattles . i have seen partial boxed in section added with plating , and ive also seen strips of metal added in a cross hatch setup , kinda like a bunch of overlapping X's . in fact , i think i saw that pic on this site a couple years ago.
 

JrSyko

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Thats what I was thinking. If you just box parts of the frame then you transfer the stress to un-boxed sections. Maybe Kris, ntsq or Fabricator can chime in here.
 

EQuin

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The Tacoma frame is boxed all the way until a little bit past the front perch of the rear springs, just a little bit before the rear axle. Maybe what the other posts have said is true about transferring stress to the un-boxed areas because I've heard of at least two Tacomas whose frames have bent in the un-boxed (c-channel) area right above the rear axle. I know that the older Toyota truck frames and the Tundra frames are boxed in all the way, though, so I don't know why the Tacoma frame is left un-boxed in that one area. But I'm no metallurgist or truck frame engineer, so I don't know.
 

ntsqd

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I would think that Ford's engineers likely spent a lot of time in designing the frame. It doesn't sound like his use is outside of the original design envelope. I would leave it alone as far as the boxing goes and just reinforce known weak spots if there are any and doing so is justifiable.
 

FABRICATOR

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This is a little too broad as to application and desired results, life expectancy, etc. The big truck frames are always strengthened by adding to the outside of the frame rail not the inside or flanged side. This way stress risers are not created. The problem here is that big trucks have straight frame rails and everything smaller usually does not. Low riders plate the inside and/or outside with good results, and pound their frames as hard as we do. It would seem much less safe on a pickup because of the split body. There is much discussion of the topic on various off road web sites. One is boxing frames Be careful with it.
 

partybarge_pilot

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Our pre-runner bronco has a partially boxed frame. It's nickname is now "the crack rental companion of the evening". If your going to box it, go all the way.
 

Ryan B

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On povey's old bronco (that he raced for 21 years with the same chassis) he only boxed around the engine/frontsusp areas and in the rear above the axle. I know it never broke because he still has it today. So on your brothers truck that won't be raced I don't think he'll have any problems.

Yes the same truck for 21 years badass
 

Jerry Zaiden

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These two pictures are the first truck we built "not the one we raced" Lets just say we wished we plated the frame on the one we raced.
 

Kritter

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The accident would have been more violent on you and the co driver if the whole frame was plated!
 

Jerry Zaiden

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NO............

It would have been just as violent but the frame would not have "buckled"... The frame is now plated in and will last way way way longer than a truck not plated in.
 

Kritter

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Energy was lost during the buckling of the frame. A rigid frame would have transferred the energy elsewhere and that could have been transferred to your neck and back and paralyzed you or your co driver. Just because a frame is rigid, it doesnt mean that the energy is just dissipated (that would violate the law of conservation of energy ...it just goes to the next weak link in the vehicle! I would say the human body is the weakest of all links (and the most expensive to fix) in a vehicle during an accident! Cant defy physics by boxing in a frame, but you could save some headaches (maybe not in an accident) of a bent one!
 

Greg

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Jerry, where exactly did the frame buckle? was it near one of the radius arm attahing points? or one of the 4-kink mounting points? or where the cage mounted to the frame?
 

ntsqd

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Kris, while you're right about Energy Dissipation, that's too hard of a call to say it would effect the occupants differently if the frame were/weren't boxed. I do see where you're headed though, you're saying the boxed frame would affect that rate of dissipation which it would. But that is only a part of the total picture.
It would be much more dependent on the nature of the crash. E.G. if it were a side-over roll on a dry lake bed vs. stuffing it head-on into a rock outcropping. The Rate of the dissipation is crucial to the injuries sustained.
 
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