Well, it didn't just crack. It ripped.
33" spare and hi-lift on a Nates bumper/tire carrier. The frame tie in bent as well due to the added leverage. Luckily the bumper stayed on until I got home.

















Plan is to open at the frame rail, insert 2x4 .250 wall and attach to rear bumper. I've seen this done on a few XJs, but I can't tell if any of them utilized the factory 8 mounting points in their reinforcement. If not, then I am okay.

Next, how do I fix this? Besides beating it back and welding it.

 

Did you use the factory receiver hitch mounting bolts and nut strips when you mounted this? I didn't see any photos of them and what they looked like.


My rear swing out tire carrier bumper with 33" tire and Hi-Lift jack (not Nates) has no issues at all but used all mounting points for it.

 

I did what you were thinking of doing, I utilized the holes that you would use to tie in the trailer receiver.

 

JCR nut strip. I have HD Offroad shackle relocation brackets too. Those are bolted where the hitch would go. And Nates bumper has a frame tie in under the HD brackets.

 

Wonder if the relocation brackets had anything to do with it?

 

I doubt it. The bumper frame tie in is 1/4" flat bar. There is no support for vertical movement other than the factory mounts. The bouncing offroad, I believe, and the weight of the entire bumper and accessories caused the mount to rip.

Had I caught this sooner, I may have been able to prevent this. Also, this bumper is heavy! Weighs around 130 with carrier. Add the 33 and jack, and this thing is a lot of over hung weight when the carrier is open.

 

This weekend I will begin the repair by welding what I can, hopefully all of it. And cutting the frame rail opening so I can tie in from the top and bottom.

I have contacted Nate at Nates4x4. This is the first time He has experienced this with his bumpers.

Question for those fabricators out there, how would you tie in the frame mount to the bumper? Would I just weld it to the flat plate (that mounts to the factory points)?

I've been debating on selling this bumper and getting a different one that utilizes an internal frame mount as well as the lower so it sandwiches the frame. Dirtbound, Warn and Hanson all have mounts inside the frame and under. Plus they are not as heavy. I think 2x6x1/4 is a little overkill. Even my front bumper is heavy.

 

do you really want to sell your problem to someone else?
if you like your bumper, why not just modify it? it is simple enough if you have a welder or know of someone with one.

that's what i would do. it looks like a well thought out bumper design, why start all over again?

if you want, you could always get a replacement panel from a donor jeep and weld that in place of your ripped one, then with the modified bumper, bolt that in to the frame rails and you're better than ever.

 

I also ran posts inside my frame and used 3/16 plate sandwiching the unibody. I also used the 8 factory bolt locations. My hdo no lift relocators are tied into the bumper also.

 

Good point. I don't think it's the bumper that is the problem, but metal fatigue. I've talked to Nate, he is looking at some design changes but with this being the first problem I don't think it will change much if any.

The lower frame tie in is 1/4" flat bar. This bent along with the bumper ripping the top 2 bolts. I'm thinking of welding angle iron to it for reinforcement.

I wish I knew a welder in southern Utah...

 

That flat bar on the bottom isn't doing much on the bottom for vertical loads. It will help keep it from pulling the back panel off in horizontal load like towing.
I would definitely get something taller inside the frame rail like everyone else is suggesting. If you're going to weld all that back together you should probably go ahead and overlay a piece of steel over it or replace it all together so it doesn't just crack next to the new welds.

I added these inside on mine and once I get the gas tank skid in place I'll have another 3/16" on the bottom to sandwich the frame rail.

 

I agree with the above, I am pretty much running that same setup with no problems.

 

Instead of 2x4 or 2x3 I might just use c channel and weld the nuts to it. And use c channel on the lower frame tie in as well to minimize the lateral movement.

Wish I thought of this before installing the bumper! Then I probably wouldn't have any damage.

 

It's pretty irresponsible that anyone even offers recovery or tire carrier rear bumpers on XJs without tying into the inside of the frame rail. What happened to the OP is inevitable and the stock location simply wasn't engineered for that sort of stress.

As for using the stock 8 bolt holes, yes, you'll need to for vertical support for the TC. Gusseting the tube inside the frame rail really isn't enough.

 

Suggestions for vertical support? I'm getting ready to patch this up, and cut the opening so I can add support to the inner frame. The bumper has a frame tie in under the rail and mounts to 3 bolts on each side plus the stock 8 bolts. Would welding the inner frame tie in to the mount (where the factory bolts are) be sufficient? Basically it will clamp the frame rail when installed.
Others seem to just mount the inner frame and factory bolts.