The Stovebolt Site Forums The Shop Area Paint and Body Shop Bumper to Frame Issue

The bumper on my truck tilts towards the left. After installing new leaf springs and equal tires, the problem still exists. The problem is that the frame is twisted towards the rear. At the cab back end, it is straight and level. My solution is to shim up the droopy side cross rail so when I install the bed sides it won't be noticed unless you look underneath. You can see from the attached pictures, to level the bumper, I had to drop down the right side. It looks like there still may be enough metal to drill new holes. I've never attempted to drill through that kind of steel. Can it be done with a good quality drill bit? If there is any other solution aside from taking it to a frame straightening shop, I'd like to hear.

The last two pics are the left side bolted up to be left as is.

JoeDude, I think your question may get better answers in the Paint and Body Shop, so it's been moved there for further conversation and help.

Is that giant steel cylinder the bumper? Install a stock one and double your fuel economy.

Yep, it's the bumper. I'll guess that it is hollow since it looks like end caps were welded on. I haven't had the truck roadworthy yet. Looks like I will be finding out this year how bad the gas milage is.

My guess, somewhat based on experience with a bent frame, is unless the frame is straightened the fender fit will also be challenging. A good body shop with a frame machine can likely fix the frame. It’s been six or so years since I had it done so costs may be different now. Back then the charge was less than $300.

As far as drilling holes in the frame, that's not an issue, as it isn't hardened steel, just regular steel.

But the correct approach is to get the frame straightened. Shouldn't take much. A laser level and some cross-measurements will tell you if the frame is tweaked. The Shop Manual has dimensions for checking the frame for straightness.

Hahaha! I thought it was a solid cylinder. I guess its a lally post someone welded up.

Straightening a C-channel frame isn't rocket surgery- - - -all you need is a piece of H beam, some high strength chains, and a couple of 20 ton bottle jacks. Figure out where the bend is, and push and pull things until a few plumb lines and horizontal bars attached to the rails line up visually. That procedure was used long before lasers and other high tech equipment existed.
Jerry

Jerry's right, you don't need a lot of high tech stuff. But doesn't everyone have a laser level?
I've done some minor straightening with just a ball joint press (just for small bends.)

If you have a torch , and know where the twist is you can apply heat and lay some weight across the two frame frame rails. with the majority of it on the bent up side.
Heat the c channel and the frame will start moving down on it's own . Sit a block about 1/8" below the desired height until it reaches the block.
As the metal cools it will pull back up within a decent tolerance.
If frame is bent downward do the same process in reverse using a jack to lift the twisted side.
Side not having the vehicle level and laying a level across the frame helps tremendously.

A frame should only be straightened cold, without heat. If it's bent enough that the metal is stretched, then it's probably not safe to use.

Dad's business partner, who supervised a battle damage rebuilding depot in Belgium for 6X6 trucks and other vehicles during WW II had a different approach. Big chains, 20 ton bottle jacks, and a rosebud torch in both hands. I've seen him get a foot of frame rail cherry red at times, with no ill effects once the wreck was rebuilt. These days, the frames made from high strength alloy steel the thickness of Saran Wrap won't stand that kind of straightening!
Jerry

Jerry, that was a different era. The terminology used in the Military was "Field Expedient." The emphasis was to get it back in service as quickly as possible.

Here's a clip from the 48-51 Service Manual.

STRAIGHTENING FRAME
In the case of a collision or accident when the bending or twisting of a frame is not excessive, it is permissible to straighten the frame. Use of heat is not recommended when straightening frames as heat weakens the structural characteristics of frame members. Therefore any straightening of frame members should be done cold. Frame members which are bent or buckled sufficiently to show strains or cracks after straightening should be reinforced or replaced.

He spent two weeks trying to straighten the frame of a then-new 51 Pontiac that had been about 50 yards from a dynamite truck explosion. A local body shop had bought the car to rebuild with a salvage title, and they decided to get the frame checked out. Although all the windows were blown out of the car and the driver died in the accident, the frame didn't look bent. None of the replacement body panels would bolt on, and he finally had to give up on the job. There simply was not a single area of the frame straight enough to use as a reference point.
Jerry