Why you should be careful with frame mods

[m16ty]

Here is a perfect example of people doing frame modifications that don't know what they are doing. https://www.govdeals.com/index.cfm?fa=Main.Item&itemid=352&acctid=1941

What they did was welded in a crossmember (to support a toolbox) and caused the frame to crack. Even looks like it has cracked before, and instead of getting rid of the problem, they just added more weld, which still didn't work. It all boils down to if you do a frame modification that can't flex, it will break every time. Also, as a general rule, you should avoid welding or drilling on frame flanges

[Rob]

Not too difficult to repair properly once the offending material is removed but someone certainly didn't know, or didn't understand the dynamics to correctly to modify truck frames.

[Vladislav]

Ufff, I would like to know the way to connect two parts of a frame rail avoiding welding or drilling of flanges.

The only solution is seemed to me is to avoid frame modifications. Which I see no way to avoid though

[m16ty]

You can weld flanges, such a lengthening a frame, but in most instances it's a bad idea. That's why I said "as a general rule". It's never a good idea, that I can think of, to drill a frame flange.

To add a cross member as in the example above, the correct procedure would be to bolt it into the frame web.

You'll have to weld the flange to fix that truck. It will do no good though if you don't remove that cross member first. What I'd personally do to fix that truck is remove the cross member, grind all that mess off, weld the frame up, and then have a frame piece formed that will fit inside the existing frame, and bolt it in. Other people have other ways but that's they way I've always fixed them and haven't had any problems.

[Truck Shop]

                                        I have done over seventy frame stretch jobs through the years. The minim length for inside rail when I do a lengthening is six foot and that

                                        depends on where the crossmembers are going and suspension will set, some are 7 & 8 foot. I spend allot of time on fit-up where the two

                                        rails meet and preheat rail before welding. I use a six 5/8 flange bolts at the joint and like to have a crossmember at that joint.  I only use

                                        flange bolts for fasteners. Plus I use car reamers for final size. Inside rail should fit tight.

 

                                        Truck Shop 

[Ezrider]

i would just take that cross member out, grind that mess off of there stop drill the end of the crank v the crack out probably 95% of the way out with a angle grinder give it a bit of a pre-heat and then mig weld it probably 1-2 inch at a time and peen each section of weld as you do them and i would be 99.9% confident in that repair without doing a frame insert