Frame Boxing Questions

[Cow Mountain Wheeler]

Howdy all, I was looking at my bare 77 half ton shortbed pickup frame last night, and had a couple head scratchers that I cant figgure out what to do.

First of all, I was looking at my engine mounts. It seems that in order to get a good strong brace around that area, Id have to weld directly to the mounts. Would I be regretting that decision in the future? And,

I would have to torch a hole in the passenger side engine mount, or run the brake and fuel lines under the mount. Is there any trick to that that I could be overlooking?

I'd appreciate any input. Thanks!

Evan

 

[boz42]

If you are convinced that you want to box the frame, & have read all the pros & cons, then realize that having gaps & or holes in the boxing will not weaken it. It does not have to run solid the entire length of the truck. That would just be extra wieght.

 

[Cow Mountain Wheeler]

Yeah, thats another point I meant to bring up. I had taken the weight issue into mind. Where would be the most strategic places to box? Also, besides the weight, what would be some of the cons to boxing a frame? You'll have to excuse my lack of knowledge on this issue.. This is a new one to me, but somehow I have it pounded into my thick skull that I have to do it. And I know better than to argue with that, haha.

 

[boz42]

How are you going to use the truck?

 

[Cow Mountain Wheeler]

How are you going to use the truck?

Its gunna be an all around offroad rig. Mainly gunna be used on some local trails where it will be flexed out quite a bit. But when Im not using it as a trail truck, Id like to do a little rock crawling and mud bogging here and there.

 

[boz42]

Well IMO boxing the frame is useless unless you tie the whole thing together with a cage. If you stiffen the frame by boxing I would say it would only stiffen it enough to tear rivets out of the crossmembers. Welding the crossmembers in would not help either. I believe it would just crack the welds.

If you boxed it & then tied the entire thing together front to back with a good sound designed cage then that would solve the problem. Really just a cage would solve the problem, & that would also be dual purpose.


If you must box,

 

[sandypants]

I'M Suprised that there is no tech artical on this one. espically pointing out pro's and cons

 

[dyeager535]

Box it all the way or don't box. Anywhere its not boxed, will break.

New trucks are not caged, but are boxed. It works. Problem is, the bodies are *probably* stiffer, whereas these older truck bodies have very little rigidity, as evidenced by how much they allow the weak frames to move.

Weight is of little concern. I calculated the weight out before of using 1/8" steel (which is equivalent to the 1/2 ton frame thickness) and it's something like 126#. Not much when talking 5K+.

Here are a few threads:
http://coloradok5.com/forums/showthread.php?t=238128&highlight=boxing+weight

http://coloradok5.com/forums/showthread.php?t=249708&highlight=boxing+weight

http://coloradok5.com/forums/showthread.php?t=140818&highlight=boxing+frame

 

[Cow Mountain Wheeler]

I like that frame trussing idea. Any input on that? Seems simple enough, and with some 2 1/2" thick wall DOM tubing as some cross members, that should be plenty strong, right?

 

[dyeager535]

I like it, as long as the space between the truss still allowed you to get at whatever bolts you need, etc.

I will be boxing my frame somehow (body off), but I'm wondering about the truss idea. I would expect the angle of the metal needs to be 45* to the frame for best strength, which isn't 45* from horizontal anywhere the frame is bent, but any tool you can set at a 45*, with a flat edge would work.

Those that work with metal quite a bit, I'd like to hear what you think would be the best way to accomplish the truss idea. I'm thinking cut a piece of steel short enough to work with, find the angle, tack the top of the "truss" piece to the frame, tack the bottom, then use a plasma to cut the pieces that protrude, then do the final weld.

I suppose if the C-channel of the frame is the same height all the way, you could just as easily square cut a bunch of pieces of steel the right length (assuming you don't have a nice metal saw) tack them in place and plasma cut the protruding edge top and bottom, then finish weld?