'68 rear frame repair advice

[calgary68]

My new to me safari twin took a rear impact at some point and the frame is bent an low by about 2.5" in the rear. It's not really an issue inside as the support is below the sink and the floor is pretty solid. It just looks awful.

The frame itself is not torqued (they checked it over before installing my new axle).

If I use a jack, I can bring it up to height, but once the pressure is released it just sags back down and I can't over bend it without damaging the shell.

I think I will have to pull apart the corner cut and re-weld or possibly cut part way at the bend and then bolt a brace in or something...

Any other suggestions?

[Iansk]

Hello,

If it were my dilemma, I'd explore installing a rear hold down plate like what is in front. It would involve removing whatever is just inside your back window and the lowest inner skin to be able to buck it together with the shell. At the same time I may remove the rear most belly pan to see if I could see any bends or stress fractures in the frame and consider welding on some stiffeners.
All this being done while the frame is jacked to level side ti side and front to back.

That's what I'd do...

Ian

[Belegedhel]

Are you sure you don't just have an advanced case of "rear-end separation?" The shell should be firmley attached to that rear cross member (I would expect), so you have notonly a sagging frame rail, but no connection between your shell and the rear part of the frame.

I would suggest dropping the belly skin in the rear to get a complete picture of the frame back there, and how it is/isn't attached to the shell. Also of consideration when talking rear-end separationis the condition of the subfloor in the rear. Has it been repaired/replaced/patched? Was the repair done correctly (with the floor being sandwiched between the frame and the shell)?

Good luck!

[calgary68]

Thanks for the advice, I did pull back the belly pan last night for a closer look, here are some notes:

The floor is original and notwithstanding being currently wet from what I think is a leaky window is solid. It is sandwiched between the frame and shell.

The rear bumper is bent, so whether it was the cause or not, there was a significant impact in the area.

The angled piece of metal in the forward bottom area of the bumper box is bent as well.

Just behind the axle mount, the frame was cut at some point and re-welded - this vertical weld only exists on the side where the frame is separating. So it looks like someone attempted to repair this historically - perhaps at the time of the accident, but maybe not properly such that the symptom is now rear end separation...

I have some interior work to do to get it ready for the season, but this is bugging me, so I may try and address this soon if I can, but it may have to wait until the fall.

The underside has a fair bit of sprayfoam in there making me nervous to crack out the welder without really committing to the repair and pulling everything apart - but I may try to jack the rear, recut and reweld the weld from behind the wheel and then weld a 1/4" plate over the area for strength.

Is there a cross member in there that I will be fighting with this approach?

[calgary68]

Argh, so whether cause by an impact or not, I tried the bounce test on the other side and I do have some movement of the bumper independent of the shell - so, rear end separation is my reality now. Its going to have to be a fall repair.

To make the trip to the Yukon this year though, I am going to split the frame where the old weld is, jack it to level, put a steel plate on top of the floor and bolt through to the frame and then reinforce and re-weld the joint on the frame - hopefully that will last until I can pull it all apart.

[Wabbiteer]

I found the frame 'C' profile ladder rail is very vulnerable if one of the narrow flanges is dented - in my case Joe Somewhen tried jacking/lifting the trailer on a random section of frame rail aft of the axles, what that did was insert a pleat to the rigid frame and draw down that sides' bumper mount one-inch, an incredible stress pivot point that just wracked a warp into shell/floor/frame neat as could be.

After everything short of torching it red hot and blacksmithing or holding it true in a jig and cutting/welding, we used hand sledges, 18" crescent wrench to trap 3/32th flange ribbon and rock it back near true etc. there is still a 1/4 or 5/16 inch drop to bumpers right side, just from a little dink two-ish feet from axle mounting plate....