4x4 Labs rear bumper frame bracing? (1 Viewer)

[1973Guppie]

Hi All,

On last years rubithon trip I found out the hard way that the labs rear bumper WILL move sideways into the body of the truck if hit hard enough from the side and from flexing. I have since learned that the bumper needs to be braced against the frame on each side to compensate for this. Was wondering what others have done for this issue and if any pictures are available. I have some ideas already but always like to see what others have done. Thx much.

Noah

 

[Rwhat]

Gusset the bend on the inside of the bumper. Or trim off the tube on the wing of the bumper that’s hitting the body.

 

[1973Guppie]

spoke with 4x4 labs on this, seems like they have seen this happen in the past, probably a little of both the body / frame flexing and the wings flexing. I think I am just going to live with it. May tackle it in the future if I end up pulling the rear bumper someday.

 

[1973Guppie]

Gusset the bend on the inside of the bumper. Or trim off the tube on the wing of the bumper that’s hitting the body.

it may be possible to gusset the interior of the bend but the body is fairly close to the wing. After looking at it today, I agree this could make sense to do when I remove the rear bumper in the future.

 

[Tools R Us]

The body is soft mounted, moves significantly, bumpers, etc, need to have clearance to allow for the movement.

 

[baldilocks]

spoke with 4x4 labs on this, seems like they have seen this happen in the past, probably a little of both the body / frame flexing and the wings flexing. I think I am just going to live with it. May tackle it in the future if I end up pulling the rear bumper someday.

On my first attempt, I welded a 6” piece of 1/4x3” flat bar across the bend in the wing. That helped a little. So then I removed the bumper to weld in a piece of 2x2x1/4 square tube vertically to the wing and against the frame. I mean, welded to the bumper only and very far forward and riding against the frame. To that I welded a rib that I first mocked up with cardboard that reaches outboard and curves up with bumper but not all the way up to the horizontal tube that’s on the bumper already. Off of that rib, I weld some shorter pieces that run longitudinally for support. This helps tremendously but is not ridged enough to withstand the amount of force that a loaded 80 can exert when she’s in a pinch.

Ultimately, my stiffener got mashed into the body and caused more damage than I had from just the original tube. No doubt that it helps but only up to a certain point. If you do a lot of Rubicon style wheeling my suggestion is to chop the lower portion of the rear quarters off so you have room to run tubing straight to the frame. If not then I’d leave it alone. Besides, once the body damage is done, there has been clearance made between the body and bumper

 

[1973Guppie]

On my first attempt, I welded a 6” piece of 1/4x3” flat bar across the bend in the wing. That helped a little. So then I removed the bumper to weld in a piece of 2x2x1/4 square tube vertically to the wing and against the frame. I mean, welded to the bumper only and very far forward and riding against the frame. To that I welded a rib that I first mocked up with cardboard that reaches outboard and curves up with bumper but not all the way up to the horizontal tube that’s on the bumper already. Off of that rib, I weld some shorter pieces that run longitudinally for support. This helps tremendously but is not ridged enough to withstand the amount of force that a loaded 80 can exert when she’s in a pinch.

Ultimately, my stiffener got mashed into the body and caused more damage than I had from just the original tube. No doubt that it helps but only up to a certain point. If you do a lot of Rubicon style wheeling my suggestion is to chop the lower portion of the rear quarters off so you have room to run tubing straight to the frame. If not then I’d leave it alone. Besides, once the body damage is done, there has been clearance made between the body and bumper

thx for your insight and experiences, yeah I think I will just let it be. I like the scars on my truck anyhow and the reality is I am too damn busy working on other peoples cars to be messing around with mine other than keeping it operational.