Driver’s Side Rear Torque Box

(Work done around Dec 2015-April 2016)

One of the main things that added some extra unplanned time to all the work was the replacement of the driver’s side rear torque box. The frame rail on the original one was in really bad shape from rust. I started poking around on it and it started crumbling away. I already had a new one in the garage, so that was nice at least. I had planned on replacing it a few years ago, while I was doing the floor pans and everything like that. I just ran out of time that summer and haven’t had much of a chance (or the desire) to mess with it since then since it’s rather invasive.

Replacing that was annoying, just like it was when I did the passenger’s side one awhile back. I stripped the interior and pulled the gas tank since a lot of the welding would be on the frame pretty nearby. Then I made several measurements so that I could position the new one as correctly as I could, with most of the measurements focusing on the position of the leaf spring mounting holes. Additionally, I just marked a spot on the garage floor directly below the mounting hole on one side of the frame rail as another reference point. Then it’s just a matter of partially cutting out the floor above the frame rail section, drilling out the spot welds between the floor and the torque box as well as the torque box and inner rocker, then cutting the frame rail itself to get the old box out.

Then the new one is positioned and welded in. To help make it a little stronger, I also added some reinforcement plates where the new frame rail section meets up with the original section (on the inside of the rails, so they’re not visible when it’s all together). I also ended up making a patch for the section of the floor above the torque box, as the old piece had been repaired before and seemed sorely lacking in strength. It didn’t come out as the nicest-looking repair overall, but I trust it. One day I really need to switch over to actual MIG welding instead of the gasless flux-core setup—it’s so hard to get good welds on thin metal without burning through. :/

Old driver's side rear torque box still in place
Original DS rear torque box still in place
Old torque box leaf spring mount--totally shot
Old torque box leaf spring mount—BAD!
Old torque box removed--notice the rusted frame side and overlapped replaced metal on top left
Old torque box
Old torque box removed
Old torque box removed
New torque box tacked in place
New torque box tacked in place
Frame rail of new torque box welded to existing rail
Frame rail of new torque box welded to existing rail
New rear torque box and floor patch in place
New rear torque box and floor patch in place

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