I'd like to add two D-Ring Shackle mounts to my JK Unlimited's stock rear bumper, but I don't know if the bumper would be strong enough, or would bend or twist under the pressure of a snatch strap or winch pull if and when my '07 Unlimited's mired in mud or sand. Also, would drilling and mounting the shackle mounts void the bumper's warranty, if there is such a thing? :confused:

 

I got rid of my bumper and installed an Lod. After seeing the rear bumper inside I would say NO! Your best bet get the hitch and shackle receiver. Or you can buy my OEM factory hook for cheap

 

I've thought of doing something similar, but I'm not keeping the factory bumper much longer, so I haven't messed w/ it.
If I did, here's what I'd do:

Either fabricate or buy some of these mounts like PureJeep uses (click here). Kind of pricey, so you may do better making your own if you can weld. They bolt on to the holes in the frame that hold your bumper to the frame, so no stress is put on your flemsy factory bumper. Then take a dremel or something and cut slots for the mounts to pass through. I don't see why this wouldn't work.

Edit: I just remembered the factory crush cans. You will need to check to see where these are in relation to where your mounts will go. I can't remember right off hand.