Rear Bumper Removal / Hitch Mod (for oversized spares)

[hoaxci5]

http://jeepdex.com/Commander/DOCS1/HitchIns.pdf

Mostly correct, but not totally. I didn't document this as well as I should have, but here it goes.

There are 4 "pop top" fasteners. I used a flat head screw driver to pry up the pop part, and then pulled the whole fastener out.
https://theultimatejeep.com/notfound.png

There are 2 torques (?) screws one on each side
https://theultimatejeep.com/notfound.png

At each fender flare there are 2 pinch type fasteners, I was able to pinch them laying underneath the jeep to release the bumper from the fender flares.
https://theultimatejeep.com/notfound.png

These two fasteners are what took me a little off guard, this is what Jeepdex doesn't show.
These two fasteners (2 on each side of Jeep) the center section pops out, I don't think they have to be removed completely but I did. This releases the the whole metal piece.
https://theultimatejeep.com/notfound.png

I don't think I have pictures, but there is 1 plastic rivet on each side where the bumper connects to the fender flare, I used a screw driver to push the rivet through and then pulled the remaining part out. Once all of that is complete, you should be able to remove the bumper cover. Once the cover is removed there is a plastic bumper underneath, from under the Jeep there are 2 more pop top fasteners. Then the plastic bumper can be removed.
This exposed the rear hitch. Make sure the spare tire is dropped and remove the 4 bolts.
https://theultimatejeep.com/notfound.png

I had already cut down the bolts and hitch so I don't have before and after pics. But basically you can go all the way to the welds, there is a lot of extra material there just because they didn't bother to remove it. So here is an after pic with paint.
https://theultimatejeep.com/notfound.png

And another
https://theultimatejeep.com/notfound.png

So the whole point of this mod is to allow for a larger tire to fit in the stock location, I stole the idea from Nathan (Omelet) but he didn't have a good write up.. So I (we) used carriage bolts in place of the stock Nut/Bolt setup. The OEM hitch had the nuts spot welded on to the hitch. I used a 3 lbs sludge hammer to remove the nuts, it didn't take much, but I wasn't thinking and did break my 7 pin cover. So I'd suggest removing that before hammering.

Once you have removed the nuts, replace the nuts and bolts with 1/2" x 4" carriage bolts and matching nuts. I used nylon locking nuts which I think was a mistake. I had to spot weld the carriage bolts so they wouldn't spin. Nathan said he was able to tighten his down without welding... These bolts are smaller than factory bolts, so I don't know if that degrades the towing capacity, I hope not, and it seems that really the bolts are just holding the hitch in place and really taking any of the force since the frame is there. I'm interested to see what someone else with some engineering background (cough MATT cough) has to say on this..

But the final product makes for a pretty much flush mounted hitch so that an oversized spare can fit. I don't have a final spare in location pic, because I'm still waiting for my replacement spare tire hoist winch which should be here later this week and maybe I can update then.
https://theultimatejeep.com/notfound.png

[Matt]

1) +1 rep points... i gotta do this

2) Another trick to keeping those bolts from spinning is a jab of JB-Weld underneath the head (assuming you have some time to wait for it to cure) if you don't have a welder

3) I believe this piece is "hanging" on the frame with all of the bolts in double-shear. Decreasing the size and grade of the bolt will reduce their overall load capacity.... however, if you're just replacing the middle two bolts and retaining the OEM outer two bolts, it's probably not reduced by a significant amount. I'm sure it's OK, especially since these parts tend to have a ridiculous safety factor built in to account for degradation of the bolts & frame for the life of the vehicle, and some planning for stupidity (there's always someone out there that'll grossly overload it). Do you know what size the stock bolts are?

[Matt]

Founds Omelets pictures. The hitch is hanging so the bolts are taking load. This shows it pretty good:

https://theultimatejeep.com/images/imported/2011/08/c7d23a7b-1.jpg

https://theultimatejeep.com/images/imported/2012/01/0256e650-1.jpg

For piece of mind you can get 1/2" x 4" grade 8 bolts instead of grade 5.. they're called Shaker bolts:

http://www.fastenal.com/web/products/detail.ex?sku=0167164&ucst=t

[NeilSmith]

I also thought about doing this mod. What I havent checked out yet was how far my receiver and hitch basket go up into the hitch. If they protrude through too far than it would make this mod a waste of time. So, you may want to check this first and see if you can cut them down also.

[hoaxci5]

http://www.rockcrawler.com/techreports/fasteners/index.asp

If I'm not mistaken, this is showing that each of the 1/2" bolts can take 14730 lbs shear capability, if that's the case there should be nothing to worry about correct? A hemi is only rated to tow 7200 lbs, and I understand force is different than dead weight so starting and stopping will put a larger force than the weight of the trailer. But in theory one bolt should be enough to handle the full towing amount. (Obviously I'm not recommending that, just a point of discussion and I'd like to feel safe towing..)

[Matt]

http://www.rockcrawler.com/techreports/fasteners/index.asp

If I'm not mistaken, this is showing that each of the 1/2" bolts can take 14730 lbs shear capability, if that's the case there should be nothing to worry about correct? A hemi is only rated to tow 7200 lbs, and I understand force is different than dead weight so starting and stopping will put a larger force than the weight of the trailer. But in theory one bolt should be enough to handle the full towing amount. (Obviously I'm not recommending that, just a point of discussion and I'd like to feel safe towing..)

Yes/No... it gets a bit more complicated when you start taking into account fatigue cycling and other factors.

Did you replace all 4 bolts with grade 5 carriage bolts? If so, I'd probably swap them out for the grade-8s i linked for peace of mind. If you only replaced the center two, don't sweat it but it couldn't hurt to throw those better bolts in there.

From your own link:

“When in doubt, make it stout!”

[hoaxci5]

Ugg.. once I get my replacement spare tire winch I'll have to take a look and see if the two outer bolts would hit or not.. I might just put the originals back in.

[Matt]

What size spare are you running? I recall seeing that for the outer two you just need to cut off the excess bolt to fit a 265/70/17 in there...


Edit: and another idea for those who can weld... clean up the area and throw some fillet welds around there to add support. Dont see a reason you'd want to permanently remove the hitch (and even if you did, you could grind the welds off)

[hoaxci5]

255/75/17

My welder (and skill) isn't good enough to trust for a project of this importance.. so I'll check it out and update once my winch is here which should be Tuesday.

[Matt]

I meant welding in addition to the bolts.

[hoaxci5]

Yes I know, but my welder is only a 90 amp cheapy that makes bird sh** splatter welds. So I don't think me running a crappy bead is really going to make any difference. So I'll either pay someone to weld it, or if the bolts aren't in the way put the original 2 back in.

[Matt]

Yes I know, but my welder is only a 90 amp cheapy that makes bird sh** splatter welds.

LMAO that is by far the best analogy i've ever heard


How often are you towing max capacity? I don't think you have much to worry about man.... throw the factory bolts back in before you sell it.

[GeeEssFore]

My aftermarket hitch has the nut on the other side and bolt goes through the other way

[pjmjr508]

there is a write that Sal had put up for this MOD as well. I had did and what I had to do was just grind down the excess on the outer ones & I was able to fit a 265/70/17 tire and works for me.

Nice write up

[hoaxci5]

Grinding down the bolts I still had to keep my 255/75/17 deflated to fit. Thats why I wanted to go this route. Not sure yet if it makes a real difference. If anything it's at least a rounded edge instead of a corner poking into my tire.

[pjmjr508]

my main issue was the tire sits lower than the stock one because the over-sized tire does not fit in the preformed area that the spare sat in. It does clear the bolts thoe. (Hope that make sense)

[hoaxci5]

Well I got my spare tire winch today and installed it. I'll be putting back the two outer stock (trimmed) bolts and purchasing the grade 8's for the center two. I'm planning on buying a toy hauler rv/trailer and don't want to risk it over a few bucks.