Drilling into the frame?

[CaptBuffalo]

I also posted this on FTE, but I've read more about this subject on here so I thought I'd pick the knowledgeable brains here too:

*long post warning*

I had a question about drilling holes in parts of the frame for flatbed mounts. I know that it is ill-advised to drill into the horizontal part of the channel, and the stock bed holes can get stretched out if used wrong.

So that leaves the vertical part of the frame, which is what truck body builders use. But my frame doesn't have holes in the right areas.

Another thing I've read is that drilling or welding to the frame messes with the strength of the frame and can lead to cracking, which is what I want to avoid and the whole reason I'm going to do a floating mount design.

Any tips on how to drill safely? I'm only thinking of two 1/2" or smaller holes per mount spot. And the spots I'm picking are right behind the cab, and above the rear axle.

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[79jasper]

Drilling should be no problem, IMO.

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[towcat]

you can drill just about anywhere in the vertical parts of the frame.
my rule of thumb is 1/8" to 1/4" from the horizontal bend is fair game. considering I build and run towtrucks and have yet to crack a frame in one of my builds since 1987, I think I 'm doing pretty good

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i've run all the way up to 5/8" frame bolts too.
welding? just make sure you clear the fuel and electrical out of the way.

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[CaptBuffalo]

Thanks guys. Maybe I just did the thing where you worry way too much about something that is actually much more simple

 

[towcat]

Thanks guys. Maybe I just did the thing where you worry way too much about something that is actually much more simple

never an issue asking intelligent questions.
asking the same damn questions when a simple search can find the answer? that ****** me off.
this isn't one of those cases.

 

[IDIBRONCO]

So just out of curiosity, what are you planning to do here? The second picture appears to be of a military vehicle along the lines of a 5 ton.

 

[CaptBuffalo]

So just out of curiosity, what are you planning to do here? The second picture appears to be of a military vehicle along the lines of a 5 ton.

Putting a flatbed on my truck. Gonna do a floating design so I don't crack the frame from being not able to flex in the right areas. If that makes sense

 

[IDIBRONCO]

That's starting to make more sense. The picture just threw me off, that's all.

 

[towcat]

Putting a flatbed on my truck. Gonna do a floating design so I don't crack the frame from being not able to flex in the right areas. If that makes sense

you'll need to account for the non-flat frame of the older F-series. a u-bolt tie-down with a hardwood bedding between the frame and flatbed is more than enough for our little trucks. the spring system for the duce is overkill as well as noisy when you're experiencing normal road travel since you will have two surfaces "chafing" against each other.

 

[CaptBuffalo]

The idea is to have the flatbed ride on square tube frame that is attached at 6 points, four of which have the floating design. The mounts at the rear will be hard attached. The height of the mounts will accommodate the hump in the frame. Will probably sit kinda high, but that's ok because the flatbed has a full size ladder rack built in and I don't want to have clearance issues with the cab.

I plan to use some pretty hefty springs- I've heard Cummins valve spring work well- so that the bed won't move much except for when the entire truck is twisting.

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[79jasper]

I saw this discussion not long ago. Which forum was it on?

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[towcat]

The idea is to have the flatbed ride on square tube frame that is attached at 6 points, four of which have the floating design. The mounts at the rear will be hard attached. The height of the mounts will accommodate the hump in the frame. Will probably sit kinda high, but that's ok because the flatbed has a full size ladder rack built in and I don't want to have clearance issues with the cab.

I plan to use some pretty hefty springs- I've heard Cummins valve spring work well- so that the bed won't move much except for when the entire truck is twisting.

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excessive overkill.
besides, unless you are will lubricated between the metal, the chafing you can't stop and the squeak from the chafing will drive you insane.
the payload comparison between a f250 vs a duce is great. they need extreme movement, you don't. but hey, knock yourself out. even towtrucks are bolted to the frame and in some instances, welding is added. they go through some extreme bending issues from hanging the load off the butt of the truck. :O

 

[CaptBuffalo]

https://www.oilburners.net/threads/mounting-flat-bed.60081/
This is the thread that I've read and re-read yo get info from. And this pic is why I'd like to let the frame ride independent of the flatbed. As for noise, my zf5 will probably drown out any other noises

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[FarmerFrank]

So by the time your done the bottom of your flat bed will be even with the bottom of your windows?

I always aim to get the bed as low as I can and I also bolt them solid. Hasn't caused me any grief on frame integrity or off road capabilities. But I also don't drive on sand. Ever.


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[towcat]

https://www.oilburners.net/threads/mounting-flat-bed.60081/
This is the thread that I've read and re-read yo get info from. And this pic is why I'd like to let the frame ride independent of the flatbed. As for noise, my zf5 will probably drown out any other noises

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firstly, if your girl gets muddy with you to dig out the truck.......don't ever let her go.
I used to recover the local utility co. trucks and they are dragged through stuff worse than that and they are still built the "old style" way.
but hey, what do I know.