So here's another issue that popped up because I want to run a stock style gas tank. The fuel filler/breather point RIGHT at the framerail. Recall the stock frame drops down a lot here, but the UCF rails go straight back. Another fun surprise. Again, if you run a fuel cell, this is a non-issue.

Meanwhile I got the corners painted and installed.

The UCF rails come in halves. They slide over one another and need to be welded. Note how they narrow in the middle.

Mocked up again and showing how little frame rail protrudes beyond the tub.

No way the stock filler/breather hoses are fitting between the tub and new UCF rails!

 

So now comes the bit where I'm trying to get the bumper lower without looking completely stupid. This is to help bridge the gap between the bumper and the gas tank mount.

I cut up some 2x2 square tube and trimmed it so it would fit within the bumper. This also required some trimming of the bumper parts. The goal is to bridge the front-to-rear gap between the rails and the bumper, but also lower the bumper down about 1.5".

Not specifically tied to the backhalf, but I had clearance issues between the truss and the tub at full bump. FYI, the suspension is a semi-triangulated 4 link I built in '08.

Rear bumper assembly coming together.

Here you can see the gap bewteen the gas tank skid mounting flange and the bottom of the bumper. This is much better than it was before. The gas tank has also been raised as high as it can go without crushing the hoses and connections on top of the tank against the bottom of the tub.

 

Beginning the process of connecting the gas tank mounting flange to the rear bumper.

I popped a hole in the rail to mount the front tabs for the gas tank.

Mocking everything up. At this stage, the UCF rails are still not final welded to the original frame.

Shortened the rear control arms from ~35" to 30" and installing new frame mounts.

I clearanced the rear truss to clear the frame crossmember and I also cut off the top mounting holes. This is everything at full bump.

The backhalf kit getting final welded, but the work is far from done.

 

Underside of the bumper shown. I used some 1/2" THK bar and threaded holes in it to make mounting the tank a little easier.

Mocking everything up. Notice the fuel filler/breather pointing right at the frame rail.

Ungood.

Toying with a solution.

Once I determined I'd have enough clearance (barely), I plated the outside to add some strength.

Fully welded/plated and primed. Almost ready to go back in.

Full painted...

 

Frames becoming one. I also took the opportunity to undercoat the tub.

Both sides of each rail are plated.

Checking out the fuel filler/breather hose clearances. I was concerned about the strength lost be clearancing the rails, but it's very heavily plated and I'd wager it's at least as strong as a thin, stock rail that's been frenched with shock towers.

Suspension going back in.

The rear section where the tub and rails show them being very close to one another! I decided to cut down a body mount and add it in between them. I welded a nut into the framerail earlier.

 

Now the next wave of fun hits! Mocking up the Poly Performance towers, ORI struts, and the lower mounts. Gotta make sure the strut doesn't hit the frame at full droop and the tires don't hit the strut at full bump.

I installed the lower mounts outboard as far as I could. But I needed to french the towers into the frame a bit in order to get enough tire:strut and strut:frame clearances.

Driver's side rail.

The front mount for the gas tank was in that area so I welded a nut to the inside. Easy, peasy...

I also sliced a horizontal cut into the towers to weld more of it at the top of the rails.

Front suspension mounts final welded.

Repainted the axle just 'cause...

 

Holy shit, is it actually nearing completion?? I'd been working on this project for about 5 weeks straight with 2 good friends in preparation for the trip to Moab for Easter Jeep Safari. Our departure date was now less than a week away!

New, relocated fuel filler location.

Flares installed. I also trimmed the fuel fill bezel to allow the flare to move rearward just a bit more.

Struts in and aired up (250 upper/100 lower) and taking it for a test drive 3 days before we leave. Ahead of schedule! :laughing:

Here it is the next day parked next to a stock TJ I happened across.

 

Tommy excellent and very clean work! any shots form teh rear showing the tank to axle clearance? How did she do on the trail?

 

Thanks!! The rig performed every bit as well as I'd hoped and still has great street manners, which was great news. Are you wanting a pic from directly behind the Jeep? Or a profile shot showing the axle/tank clearance?

 

So here's my thoughts... Ultimately, I really prefer the look of the flat frame rails over the stock rails with a hump that's misaligned with the new axle location. But it was a shit ton of work to do and it added a lot of complexity and time to the project. Now that it's done, however, I'm really glad I did it.

I was able to move the gas tank a little farther back and higher than with the stock rails, as well. Wheelbase is now sitting at 99" and the front is pretty close to the stock location at the moment. Pretty happy with that. I also have a little room to move the axle back if I'd like (maybe another 1/2"). Maybe down the road I'll do that....

The ORIs are pretty fantastic thus far and I haven't had to touch the air pressures since I first filled them up. I think 250/100 may be a little high for my rig since I have very little weight in the back. It's a bit rough on the street, but performed well on the trail. Really happy with the overall performance so far and I'm planning on ORIs for the front now....when the budget allows.

The Jeep did amazing in Moab during EJS. In order to soften the ride a bit on the street, I've softened the rebound damping all the way. The ride of the street is better, but I'm going to drop the lower pressure to 90 psi and eventually lower the ride height another inch. But I need new front springs before I do that. I'm also planning on 37s on 17" wheels soon, too.

So far, I've put the Jeep through its paces pretty well and everything seems to be holding up really well. I'm really pleased with it. Body roll is pretty evident since I'm only running a front Anti-rock and it's on the softest setting. Most people may prefer to run a stock bar in the rear, as well....I may feel the same way after I soften the rear air pressures!

Below are pics of it flexing to check for clearances last week. The ORIs aren't yet fully compressing and the fronts are a bit stiff, but clearances are good.

Looks like it still has about an inch of travel 'til the bumpstops.

Hoisting from the rear compressed the ORIs even less.

 

Great write up Tommy. One thing you might want to mention is the modifications you made to the cross-member in front of the tank. They were subtle changes, but the extra clearance gained is worth mentioning for those people fighting to make things fit!

I can also confirm that this Jeep did incredible in Moab! Suspension did exactly what you'd want to see, and ORI's were predictable and stable from what I witnessed. Well executed stretch and clean finish out.

 

Good point, Mark! And thanks for the kind words.....and the help!

Here the rear frame is shown upside down and it shows how I cut out part of the front crossmember to make more uptravel for the axle truss.

 

First and foremost, GEAUX Tigers! Secondly, nice job, Tommy! With the help of a great friend, my wheelbase was stretched last summer.....I'm on 37's with ORIs on all 4 corners. I chose not to go to the extent of back halving, as you did. I stuck it out with the stock frame....hump and all. In your dealings with Matt at UCF, did you ever discuss using his tank that's similar to GenRight's?

 

Sorry for the delayed response, y'all. Been traveling for work....



Geaux Tigers!! Y'know, I didn't even know Matt offered a tank. But I'd already owned my GenRight tank for about a year before I bought the backhalf kit so I was already invested in the GR stuff. I checked his site and only saw skids. Where are his tanks? I'd be curious to check them out!

Awesome work, I'm jealous of the oris. I thought about going with a backfalf kit but I ended up just frenching the shock towers and moving the spring perch. Probably would have been easier to go the route you did

Thanks! I don't know if my route would've been easier, though. It really was a lot of work, but the finished product came out so clean and uncluttered that I believe it was a great way to go! And since I don't know if I'll ever be able to sell this Jeep, I figured it would be worth the sweat!

Great write up! Makes all that work seems EASY now! Turned out GREAT!

Another subtle change was to the back side of the crossmember, it was bent further to 90 degrees to help clear the Gen Right tank. Wouldn't be needed with the GenRight tanks that are less than stock capacity.

Right?! For everyone else's benefit, Doug was one of my two buddies (along with jeepjunky) who helped me pull this off!

And you're right about the crossmember. Thanks for the reminder!

If you don't mind , what is the fuel filler bezel from and is it metal or plastic?

That's the bezel that comes from GenRight with the tank. I just trimmed it a bit to allow the flares to move rearward just a bit more.

And regarding wheels/spacers... I'm currently running 15x8s with ~3.5" backspace. I had to run a 2" spacer in order to achieve zero interference between the tires and the ORIs. I could run a 1.5" spacer and just let the tire rub the ORI at full stuff, but not sure if a 1.5" spacer is that much "better" than a 2" so I left it. I will eventually put full width axles under it, as well as 17s, and then I'll be getting wheels with a different backspacing.

 

Awesome work, I'm jealous of the oris. I thought about going with a backfalf kit but I ended up just frenching the shock towers and moving the spring perch. Probably would have been easier to go the route you did

 

Great write up! Makes all that work seems EASY now! Turned out GREAT!

Another subtle change was to the back side of the crossmember, it was bent further to 90 degrees to help clear the Gen Right tank. Wouldn't be needed with the GenRight tanks that are less than stock capacity.

 

If you don't mind , what is the fuel filler bezel from and is it metal or plastic?

 

Looks good! I agree with the flat frame rails, they definitely look better. I also like the non comp look, I wouldn't mind trying to get new corners and cut them in a more traditional jeep rear end look, and if I can justify the expense of ORIs I'd certainly get them. Have you considered an Anti-Rock in the rear?


Right now with my work schedule I don't have as much wheeling time as I did..but maybe that will change. :homer:

 

Thanks! Yeah, I'm partial to the look of a full rear fender. Not to say that I'll never comp cut my Jeep, but I'm hoping it won't come to that. And yeah, the ORIs are definitely pricey, but I'm liking them more and more as I drive them on the street. I haven't wheeled it since I got back to Texas from Moab, but I've logged a few hundred miles on it around town and the highway. It still needs a bit of tuning, but is pretty good as is.

The roll is certainly more pronounced now and will likely get worse when I soften the pressures. That being said, I drive it like a sports car so with a normal person driving it, they may never notice anywhere near the roll I see. The interesting bit is that it rolls, but doesn't feel unstable. An Anti-Rock could be great in the rear, but I think before I do that I'll look into installing the stock rear bar and see how that does. At least it'd be a lot cheaper to experiment with! LOL!