I got my monthly email from Super Scout Specialists today, and one of their featured items is a rear swingarm bumper that’s currently on sale for 10-15% off until the end of November. Their bumper is a traditional square 2×6″ tube with a tapered bottom. Their swingarm is a single piece of bent tube, hinged on the right side with a lifting bar/pin lock on the far left side. The tire mount point is directly in the center of the tailgate. I see no provision for a license plate holder of any kind in their photos. They offer several customizations, so I priced out a swingarm model with two D-ring points, for a total of $807.
GRC Fabrication sells a swingarm bumper that looks just as beefy. It’s also a square tube base, but the hinge is on the left side. The arm is two tubes forming a welded triangle, and the way they have the standoff built there’s room underneath for a Hi-Lift behind the tire. The standoff is mounted offcenter to the left, so it’s closer to the hinge and directly behind the driver’s seat, and there’s space on the right side of the swingarm for a jerry can holder/license plate. I spec’d out a version on their site with no jerry can mount and two Hi-lift tabs for $1,175. I also had the opportunity to look at one of these in person at Nationals last year, and I liked what I saw.
The big question here is: would I rather try to (re)build the bumper I’ve got, or buy something that’s engineered to work out of the crate?
Looking on the Binder Planet, I saw a build where a guy is fabricating his own bumpers, and took some pictures of the mounts he built before he installed them. It shows exactly what I’d have to do with mine: remove the two square standoffs and either raise or lower them so that a thick bar support can be welded to their bottoms which will bolt up directly to the bottom of the frame rail. This would provide a lot more perpendicular support to the bumper and eventual swingout arm.
From what I can see he might have welded the supports to extend all the way to the bumper box itself to gusset the structure as much as possible, which is a great plan.
So, first I’d have to pull my bumper off completely. This is what mine looks like now, from the inside of the bumper facing out, and from the side (body on the right side):
I’d have to grind off the standoffs and buy new box channel to reach down to the bottom of the bumper edge. Next, I’d cut new mounting plates and weld them to the standoffs. Finally, I’d build and weld two plates along the bottom of the bumper and standoffs that extend to the factory jack mounts on the bottom of the frame.
This would theoretically give the whole assembly the vertical support it needs. All of this would require removing the trailer hitch and getting some longer bolts so that the new bumper mount will sandwich between the frame and the hitch mount.
After that, I’d have to radically alter the geometry of my swingarm. The tire needs to be lowered and moved closer to the hinge so that there isn’t as much unsupported weight bouncing around. In hindsight I welded the hinge on the wrong side—If I’d been smarter I would have put everything on the left side so that the tire isn’t blocking the view over my right shoulder. So the hinge would have to be ground off, and I’d need to rebuild the swingarm from scratch—lower and left-aligned so that the center of gravity was closer to the bumper and frame. Essentially, I’d be copying the GRC Fabrication design in a simpler fashion.
I’m not confident enough in my welding skills to trust them to be strong enough, so I’d have to hire someone for the finish welding. And there’s also the cost of materials—which are harder to get these days; the local steelyard closed down and the only way I’d be able to get the stuff I need is online ordering.
I think I’m beginning to answer my own question here.
The big question for GRC is: how does their unit mount to the body? If it’s just a set of standoffs that mount to the back of the frame box, than that’s no better than what I already have. And could I use my existing hitch mount if I had a set of longer mounting bolts?