TwistedFrameRail

[glrtex]

Anyone have any suggestions on the best way to fix this problem?

I just removed my old axles, and when I pulled the old shock off I discovered the frame rail was twisted. I know I have to grind off the old shock mount first, but what should I do about the twist. Should I heat it up and try to hammer it back? Will it become brittle if I do that?
Should I leave it alone and attempt to weld the new shock mount parallel with the ground?

Greg

[57Vintage]

The mount needs to be straightened/replaced. If you leave it bent out it I would assume the shock would hit the tire/wheel. I'd also be concerned that I can see daylight between the mount and frame rail towards the top of the photo. That may be an indication the frame rail has been deformed.

Considering the damage to the tank cover I'd recomment getting the cover and tank out of the way before being inspected. You'll want them out of the way if the repair means heating the shock mount or frame rail. Be sure they know what is above the frame rail (combustible).

I'd suggest a certified welder or fabrication shop give you advice. Unfortunate that the trailer is not mobile, but having the axle out of the way makes the repair easier.

[Bubba L]

Being there in Helotes, you could contact a farm fence builder around you. They carry torch rigs and welding machines on their trucks. Like 57Vintage said, be aware of combustibles. The rail may need to be heated, straightened and a stiffener plate tacked on. Don’t know. Also metal building erectors have mobile rigs. Good luck. Bubba

[glrtex]

I own a MIG welder and I can weld, but to call myself a welder would be an insult to ever professional welder. I would remove any combustibles before attempting to heat it.
My question is really just wondering if the metal would become brittle after heating? Putting a backing plate would be OK, but how long should it be?

Greg

[DFlores]

Is the metal in the photo your axle mounting plate?

[dbj216]

Hi: I have a mid seventies "long" trailer too. It appears your trailer took a serious hit in a big pot hole or something. Isn't the shock mount welded to the "axle plate"? The frame rails are under the belly pan aluminum. The axle plate is welded to the frame rail.

Airstream made, and used to sell a "stiffener kit" for seventies trailers due to the brilliant idea to provide "lighting holes" in the axle plate to save weight. This idea weakened the axle plate and it can fracture creating the "rear end sag" that we read so much about. Other factors are involved including extra features in the rear of the trailer (water heater, battery, waste water tanks) and lousy rear body to bumper hinge plate sealing.

You are in for some serious work, but this can be repaired (like almost everything can be.) I would expose the axle plate and frame rail on both sides. Yep, the fresh water tank should come down and out of harm's way. Then you can see the total frame rail and axle plate to see how bent it is, and what it would take to straighten it, and strengthen it. It will take a skilled fabrication technician that understands metal, welding, and strengthening. Heck, the tech may decide to cut out the bend section of frame and weld in a new section with a new axle plate.

I'll be dropping my old axles on my 75 Overlander this winter. I don't think I will find a surprise like this, but it is possible.

David

[DFlores]

Thanks David, that is the direction of my question, basically get more daylight on the problem. Axle mounting plate is what I think we are looking at.

[J. Morgan]

Replacing the damaged segment and adding another piece to lap onto the straight part of the frame is going to be the best and easiest fix. You could get the bent part straighter, but in the end, replacement of the damaged segment is what I would do.

Yeah, it sounds hard, but really it isn’t.

[DFlores]

Greg, back to your question "does the metal become brittle after heating" , heating metal to a high temperature and then quickly cooling "quenching" will harden metal. Annealing metal is the process of heating to soften metal for shaping, then allowing it to cool slowly / controlled, will result in reduced hardness.
Either way, results can be tricky.

[J. Morgan]

Heat wont help that, if I were to try and straighten that, I would do it cold. But as I mentioned earlier, I would cut the affected metal out and welding in new.

[J. Morgan]

Originally Posted by J. Morgan

Heat wont help that, if I were to try and straighten that, I would do it cold. But as I mentioned earlier, I would cut the affected metal out and welding in new.

But then again I would think about it some and wonder if it might be better to augment the twisted frame while drawing it straight.

That might work if the bent rail isn’t busted or busted loose.

[J. Morgan]

Depending on how things look live and in person, a person might diligently work the frame straight with big crescent wrenches, (and like devises), and then augment a large section of the straightened frame with new steel sections.

It could be a sound and atractive repair on an otherwise serviceable frame.

[glrtex]

Update:

Being a woodworker, it occurred to me that one of my long pipe clamps might come in handy. It worked! I spanned across to the axle mounting plate on the opposite side and slowly cranked the clamp inward. I was able to get it within 98% of original. I may still weld on a stiffener after I get the fresh water tank out.

See my thread “Can of worms”.

[J. Morgan]

I would augment it regardless, once bent once, it will be easier to damage than it was before it got damaged...