Originally Posted by Geoff@Bestop
We're going to sell bumpers with a tire carrier on them, so we've been working on these things. I'm NOT saying this to get you to buy ours (which aren't out yet, anyway), just sharing:
We had to add a LOT of reinforcement to the corner where the carrier rests. The weight from a big tire is a lot, and when it's leveraged weight, sitting out on the end of a bar, then it's a tremendous amount of stress and weight.
It can really tear up welds and joints, and you're going to want to "overbuild" it.
Same thing for the pivot point. Most use some sort of truck axle or kingpin type thing. It needs to be strong.
I've never paid much attention to the stock bumper, but it may be worth getting an aftermarket bumper to build on: you may have more metal to work with.
Geoff is right on with his post. I built a back bumper for my 98TJ just because I wanted to and later decided to build a swingout. I bought the spindle, drilled & welded it in.
After a lot of work the finished product was this:
Next (below) is the bracing we did that you don't see. Besides the 8 bolts that hold the bumper to the back frame we added angle reinforcement to the outside of the frame and then welded from the inside of the bumper to the mounting plate. I can still remove the bumper and carrier because only the bolts hold it in place and if you grab the tire carrier frame and move it the whole jeep moves.
The mistake I made was adding the gas can on the opposite side of the hinge. 90% of the driving the TJ does are trails, dirt and gravel roads and vibration is constant. When I brought it down from the mountains I noticed the swing-out frame was away from the rubber bump-stop on the back door by about an inch. I think if I had put the gas can on the right side over the swivel point that might not have happened. I since have straightened out the shaft and it's back where it's supposed to be.
So overkill is better than underkill!