2008 JKU "Argenta" Build Thread (plus a 2010 Islander side project)

[pc1p]

The Motobilt Rear Fuel Tank Kit arrives today, so over the weekend, I worked on getting it ready. The first step was getting the fuel filler neck removed and trimmed out.

I was shocked that it could not be removed without lifting the tub. Since I don't need to "save" it, I simply cut it out with a Diablo Sawzall blade, using the space in the "notch" in the rear driver-side wheelwell opening.

The Motobilt tank doesn't allow the use of the factory rear sway bar, so you have to run a Currie or similar. Unfortunately, removing my OEM sway bar led to this:

I need these holes since the Motobilt rear tank skid uses them as a mounting point. So far I tried to get the broken bolts out with the "weld on a nut" trick, but it's being stubborn. I may have to drill these out and run a bolt/nut through the frame...

Update 5/27/2026
Getting back to the gas tank install, it took me some time to deal with these broken bolts. I went through about 20 nuts trying to get a solid weld onto one to get it removed, but with no luck. I ended up drilling out the bolt and the nut on the inside of the frame. I then used a step bit to open up the drilled hole to just shy of the welded "nubs" on the nut that was holding it to the frame rail. A quick whack with a chisel and they popped free.

To remedy the missing nuts, I made a nutplate that I can install from a hole in the frame, even with the bumper installed. Nothing fancy, just some nuts that matched the factory bolt thread size (this way I don't need to use a different socket on either side of the tank):

Test fitting the tank skid was easy, though this thing is a little heavy and the awkward shape makes doing it by yourself a little tricky. Luckily, the Harbor Freight Trans Jack worked perfectly for this:

The frame bracket for the AEV Tire Carrier cradles and wraps around the frame right where the rear-most portion of the tank skid gets bolted down:

A quick hit with an angle grinder fixes this:

 

[pc1p]

Had a busy few days... been trying to get the PSC hose routing, as well as the radiator hoses figured out.

Also came home with this on Friday. It's a 2022 Wagoneer Series 1. We went to look at the new Durango GT AWD Premium, which is currently on a killer 0% for 60-mo deal with Stellantis Financial, but it was still too small for our needs and this only had 5607 miles and a huge discount over new retail.

 

[Cimmerian]

Had a busy few days... been trying to get the PSC hose routing, as well as the radiator hoses figured out.

Also came home with this on Friday. It's a 2022 Wagoneer Series 1. We went to look at the new Durango GT AWD Premium, which is currently on a killer 0% for 60-mo deal with Stellantis Financial, but it was still too small for our needs and this only had 5607 miles and a huge discount over new retail.
View attachment 130803

Be careful. Stellantis build quality since covid (well before that) has been in the toilet and I've read a LOT of threads about Wagoneers in particular having so many issues.

 

[pc1p]

Be careful. Stellantis build quality since covid (well before that) has been in the toilet and I've read a LOT of threads about Wagoneers in particular having so many issues.

I’m not too worried about this one, though I did opt for the 72mo/72kmi warranty…

It seems that the majority of the issues listed in Consumer Reports (and similar) are on the fancier model tech (like the Series III and GW). This one has the stuff we wanted (5.7 + 8HP75), but no crazy extra touch screens, no auxiliary coolers, no Amazon/Alexa entertainment, etc. It’s basically a Ram 1500 with more seats, which for all intents and (my) purposes, is one of the more reliable 1500’s on the market.

And to be fair, when you look at comparable alternative 8-seat SUV’s in this size class, there simply aren’t many and they’re nearly as bad or worse in some cases. I was looking at a few Reddit boards as we were deciding and to see how many people complained about their Expedition and Yukons before coming to the W/GW was a surprise.

 

[pc1p]

Not Wrangler related, but happy to report that the Waggy got almost 20 mpg (19.8) on my trip to the Philly airport, driving the turnpike at ~75 mph there and back in "sport" mode. It's not a Honda, but from a trip planning perspective it matches the GC mileage almost exactly, and will serve us well for our upcoming family trips to D.C. and Chicago.

Also in what I'm calling the "Win of the Century", we convinced my daughter to start driving the Grand Cherokee (instead of the Islander) this summer and back to school next year. She goes to school near Philly and the traffic there, as well as the overall quality of drivers, is insane. You've got Philly people (who generally know where they're going), mixed with Delaware people who think they're on a Sunday drive during evening Rush Hour traffic, sprinkled in with plenty of out-of-town students and visitors. The Mrs. (and myself too if I'm being honest) simply were not comfortable with Charlotte taking the Islander down there on the highways. The 2017 WK2 is much safer and more stable. Thankfully, there wasn't much of a fight...

With winter (almost) over, it means it's time for some maintenance, first of which was some new shoes. We had great performance, but TERRIBLE life with the Cooper AT3x tires. They wore out fast and got noisy quickly. They also never wore smooth, despite plenty of rotations and checking the alignment three times on this Jeep over the past 6 years.

I don't tend to go with "budget" options, especially when tires are involved, but I went with these "Online Only", house-brand of tire sold by Discount/America's Tire (made by Saliun) thanks to a few recommendations. They are significantly quieter than the Coopers (even when the Coopers were new, they still very much sounded like an "A/T" tire) and so far have had great wet weather grip (I've done some heavy brake tests just to make sure I was comfortable with them). The tread pattern also very closely matches the pattern of the Evoluxx Rotator tires on the Islander, which have proven to be really good for snowy/icy roads here in the country.

Assuming they last a while, I think these will be a good option for her. We got all four installed for $413, thanks to a $$ credit we got back due to some of the Cooper tires wearing out significantly faster than their warranty mileage.

Also part of that deal was to swap out the baby radio/screen to something with CarPlay.

I had wanted to do this for some time, but could never justify the expense (at least not as of a few years ago when these upgrades were $2200+). I was able to find a 2018 Grand Cherokee 8.4" UConnect with updated "Media Center" (to replace the factory one that only have a single USB port and a SD card slot). I got the radio, color matched trim ring, and media center for ~$800.

A whopping 30 minutes later to install and let update, and it now has CarPlay, a remarkably faster BT connection, and a bigger backup screen.

The WK2 has just clicked over 110,000 miles this winter, so once it really warms up outside, I'll have some more maintenance to do before Charlotte heads back to school. It should be mainly diff service and spark plugs, though I still need to check what else Mopar recommends. It had a small radiator leak at ~85,000 miles, so it had a flush and fill back then, so I'm good there for now.

Speaking of radiators, I'm working on getting mine sorted out with the Hemi swap. I will need to make/modify some of the brackets to work with the OEM 392 JLUR cooler (above), but this looks fairly simple. Unlike the OEM transmission cooler that is integrated into the bottom of the A/C condenser, the 392 JLU unit is standalone and is at the top of the radiator, instead of the bottom.

This is a good thing since it gives me a lot of room to locate the PSC fluid cooler:

I may order the PSC "dual pass" version, which has both the inlet and outlet fittings on the same side. Given how tight the radiator and hoses are down there, it's one less thing to have to "fit"...

I test fit the Pentastar radiator fan and as expected, I have ~3/8" clearance between the fan motor and the water pump pulley. This is excellent news as it means I won't have to move my grille support at all and will eventually be able to do a proper front "chop" bumper.

With the fan fitment confirmed, I'm moving my attention to finding/making some radiator hoses. Since my hope is to run the OEM JKU radiator, I need something that connects the lower Hemi outlet (1-3/4") to the radiator inlet (1-1/2"). Thankfully, the upper hose for a Durango looks like it will not only work for the upper hose, but with a chop and union, might be perfect for the lower hose too! I've got some unions coming today, so I hope to play around with this and cross one more thing off my list...

Before I can really begin to button up the front end, I still need to figure out what I want to do with the power steering pump/belt clearance. I did some massaging of the PSC Big Bore with a 120-gri flapdisc:

This gained me maybe another 1/16" of clearance, putting me at ~1/8" total. It's better, and some people run it this way, though a number of people have talked about clearance issues and belt rubbing. I will admit that one of my frustrations with the Hemi swap has been the complete lack of DETAILED information and solution options. Many people, especially on social media, constantly shout "do a search" or "check the BOM", which time and time again shows up to have little to no meaningful solutions provided (though there are lots of questions!). Some of the solutions also seem to only help ~50% of the time, with this PSC big bore box clearance being one that seems to work for some and not others.

I needed to get some PSC parts ordered, since again their "Hemi Kit" leaves a lot of be desired and is 100% outdated and specific to one type of Hemi install (topic of another discussion/frustration). I'm going to order their 4.5" pump pulley, which they described in an email as "not working", though others have (at PSC's direction mind you) had great luck getting some extra clearance here.

 

[pc1p]

Still trying to make the OEM radiator work, but I think it's about time to throw in the towel. I cut the hose as short as I possibly could while still maintaining enough radius to actually make it clampable to the radiator:

And as you can see, there's NO way it's clearing! I threw in the towel and ordered the Northern JK Hemi Swap Aluminum radiator from Quadratec... It works with the OEM fans, which is good since I still hope to run the OEM Pentastar 17" PWM fan.

The JSS battery tray is technically a "dual tray". I'm only running a single 34-DT battery, so there was a good amount of room in the battery box. I was worried about the battery sliding around when off-roading. I found an aluminum tray that seems to work well for what I need it to do. The good thing about it is that it still works great with the JSS battery hold down (though it also includes its own hold down as an option). I got it cheap due to a clip-it coupon on Amazon!

Switching to another item on my to-do list, the rear gas tank hatch and cover:

It's super thin, only 16-gauge:

As you'd expect being so thin, there's a worry about blow through and warping. As a result, I stitch welded the underside while the top panel was screwed to a set of 2x6" boards. This seemed to help but did get a small bit of distortion, nothing that will be noticeable however once secured to the tub.

 

[pc1p]

I gave up on the idea of keeping the OEM radiator - that outlet was never going to work for me. So, as much as I despise the thought of an aluminum radiator, I ordered the Northern made one meant for the Hemi swap. These have the best track record and I used new bushings that should help with flex-cracking.

Even though this is meant for the Hemi swap, the lower hose outlet still needs to be trimmed for use on LX/Car based Hemis (the outlet works fine as is for truck VVT engines as the alternator is located much higher). It's not hard, but taking a Sawzall blade to your new $800 radiator is a bit anxiety inducing...

You can see the angle here is much better for clearance compared to the OEM (which is physically higher AND points "up"):

I used some electrician pliers to put a crimped bead on the outlet to give the hose clamp something to ride against.

With the radiator secured and modified, it took me about 4 days of trying, trimming, parts-store-searching, and mock-ups to make a hose that sits perfectly in place and clear everything:

What you see is actually two DS72019 hoses unioned together. Check out the Hemi swap page for more details: https://wranglerjkforum.net/threads/jku-hemi-swap-reference-guide-swap-info.32731/post-472868

Everything clears, so now it's time to start reassembling the front end. I'm working on the rest of the wiring connections today (I left them off so as to be out of the way for radiator and hose work), and am going to get the A/C lines (at least at the compressor) buttoned up. It's TIGHT down there, but so far, everything does look like it should clear.

 

[pc1p]

Had a busy Easter weekend - the family took a road trip to D.C. to catch the Cherry Blossoms and explore around. It was quite the adventure and we packed a lot in: Goddard NASA Space Flight Center, Arlington National Cemetery (caught the changing of the guards at the Tomb of the Unknown Solider too!), tidal pool (no cherry blossoms unfortunately), a bunch of the monuments, the Smithsonian Air & Space Museum, a bunch of good food joints, and more.



In case it was ever in question, here's a picture of me being a nerd at the VAB, almost 11 years to the day of the Artemis II launch and a month before they announced the Artemis project conversion (I was working for the DoD at the time and had some work to do at Cape Canaveral, and they just let me drive around!).


We're all science nerds in the house and my son is a plane/rocket nut job, so he was in the clouds for a good portion of the trip. Thankfully, before we left, I was able to get some time in the garage to keep the project moving along... First up was getting the Motobilt Rear Hatch painted, seam-sealed, and installed:

Timing wise of the trip, it worked out well, as the sealer had 3 days to harden without me touching anything...

After getting the radiator hoses squared away, I've turned my attention to the A/C lines and PSC cooler. First step was installing the condenser on the radiator and checking fitment. Looks like I'll need to do some trimming here:

I got the lines from JSS and the fitment was, well, less than great...

There was a big kink in the high pressure hose (and this was after "manipulating", aka bending the shit out of, the tubing portion to get the best fitment):

And the suction hose was worse - not only did it have a kink, but it hit the booster, the bracket on the firewall that held the wire harness, and it rubbed on the engine oil dipstick. Supposedly, this is "fine" as the system, when pressurized, will "fill in" the kinked portion. After picking the brains of others on the JSS Facebook page, I realized that people get it to fit in the best possible way it can for their configuration, and then use zip ties and spare rubber hose sections to keep things from rubbing holes...

For me, that's totally unacceptable. I don't want to be driving, constantly worried about "is the zip tie holding"? Plus, with a kinked hose, how are you going to evacuate the system well? It didn't make much sense to me to "just deal with it", so I took matters into my own hands (which is what it seems like I'm doing with this swap for the most part). I ended up cutting the ferrules off the ends of the JSS A/C hoses, at the evaporator and at the condenser:

After manipulating the tube into the "best fit" shape, I figured out that by cutting off ~2" of each hose gives a perfectly "neutral" fit, with no tension or compression on any of the fittings or hoses, and with ZERO rubbing anywhere:

I ordered some ferrules and a crimper from Amazon, so once I'm back home later this week (currently on a work trip), I'll get these crimped up and secured! Once these are done, I can turn my attention to putting the final touches on the PSC steering lines and mounting the PSC cooler:

PSC says to install it as you see above, just in front of the condenser and behind the grill. This seems foolish to me, and many people have complained about overheating their engines AFTER doing this (and not before), so I think there's a better place. I'm going to "flip" it, and install it UNDER the radiator support bar. It should have plenty of protection from the bumper, engine cradle/crossmember, and steering stabilizer, but shouldn't impede airflow into and through the radiator (I'll make some aluminum panels when I'm all done to replace the hardened plastic/rubber "dams" that came from the factory.

 

[pc1p]

I got the A/C lines trimmed up and re-crimped...

Everything fits great now, with no rubbing on anything and away from significant heat sources...

The pressure switch installed on the suction line is a little close to the exhaust manifolds but supposedly doesn't cause any issues:

Even still, I decided to add some loom and aluminized HVAC tape:

With the new radiator in place, the lower hose was really close and rubbing on the OEM body harness connector. To remedy, I simply drilled two new holes about 1-1/2" away from the original ones:

I'm going to keep working on reassembling the front clip - I am waiting on some new #2 AWG terminals (5/16" stud instead of the 3/8" I bought), but should have all the wiring done this weekend!

 

[pc1p]

Radiator hoses and A/C lines are done, so I'm turning to the battery cables.

I'm using tinned copper, 2AWG cables for basically everything, except the battery-to-inner-fender ground wire, which is 4AWG for easier routing (still larger than the factory ground wire, which is #8AWG).

The OEM configuration uses a fusible link on the cable coming out of the alternator to the battery. Since the Hemi is running a large 180A alternator, I wanted to run #2AWG wire, which necessitates the use of a Mega Fuse. I installed it on the JSS intake box, close to the alternator but safely out of the way of moving parts and other items. It's easy to get to, but also protected. I have the cable coming out of the alternator, sneaking through a spot between the alternator itself and the cylinder head. I covered this wire with some heat reflective, fiberglass heat sleeving. I may reroute this cable around the outside of the alternator if, when I finally install the front inner fenders, it clears sufficiently.

I'm running the 34-DT series battery and want to be able to run the winch cables up through the radiator support to the battery. It's tight, but not as bad as it was when I was sneaking the winch cables around the TIPM and intake box. As I was working the cables, it occurred to me that the EVAP purge solenoid was almost directly in front of the + side terminal of the battery. Flipping it around made more room, and allowed for better hose routing, but the connector no longer reached. Some solder and a few short pieces of 18 AWG wire took care of that issue:

Battery cables are done, next up is the rest of the power steering lines. I ended up using some 1/8" steel angle iron to make a brace across the frame rails. The PSC cooler will sit on top of this, and be completely "free" of the radiator support or grille. This will let me service those items without having to crack open the PSC cooler lines.

Lots of room in the back between the cooler and the condenser:

I threw on the bumper and winch just to confirm clearances before fully welding the brace in place. I've got a lot of room and can still likely go with a frame chop at some point...

This bumper was cheap but I still like the shape and style...

Remaining items before my test crank:
- I need to trim the plastic pieces on the radiator support to let the Norther Radiator and A/C condenser fit flush
- Replace the remaining cracked loom at the front of the radiator support
- Connect the PSC cooler hoses and bleed the system (a lot easier when the radiator and grille support are off for the last time!)
- Reinstall the intake manifold and hook up the last few harness connectors (e.g., MAP sensor)
- Reinstall the radiator and fan; connect the A/C lines
- Determine if the JL392 trans cooler is feasible; either install or find alternative and connect trans cooler lines
- Install the RPM Extreme Fan Controller and Pentastar Fan harness; tap into CANBUS (also needed for TCM)
- Swap out ECM for JSS provided Hemi ECM (when it arrives)
- Install and wire up the JSS 8HP TCM

It's getting close, but also feels like a lot of work remaining when I start listing it all out. Still, I'm excited to be closer to the end than the beginning. Since I installed the engine at the same time as the axle swap, there are some other items I will need to do before my first drive (e.g., align the steering, bleed the brakes again, bleed ABS, etc.).

 

[pc1p]

Well, what I was afraid of has happened - the delays have pushed the Hemi swap into the spring and into my second busiest time of the year. Between leagues shoots, team coverage, and end-of-the-school-year activities to cover (e.g. prom, graduation, etc), the Jeep unfortunately gets pushed down the line.

But - at least I now have everything i need to cross the finish line, er, well, at least get me to a test start soon. The JSS ECM and 8HP trans controller and wiring has arrived.

I've started running the wiring for the trans, including getting the PCS controller mounted. Many people just use two sheet metal screws on the back end of the controller, but that seems a bit ghetto for me. I ended up drilling some holes and installing some 1/4"-20 rivnuts. I actually ended up using three rivnuts, two for the TCM itself, and a third underneath that will let me use some sort to spacer nut/push-clip to help support the front of the controller. This, combined with two nylon 1/4" spacers will allow the PCS to float above the floor pan and stay away from the heat.

I need to run the power, CANBUS, and other wires, plus a couple to the ECM, but this will hopefully be done this weekend! My goal is to get a test-fire by the end of next weekend... fingers crossed!

 

[pc1p]

Some good news - I was able to test crank (not start, just crank!) the engine!

I got the C3 connector (the body harness portion of the ECM wiring) updated with the wires from the JSS harness... I gotta say, these aren't nearly as tough as the older JTEC connectors. These broke and I was even using the proper tools!

I think I found a home for the RPM Extreme PWM Fan Controller... it's close to the ECM, away from heat, and protected from the elements:

I have only temporarily connected the trans wiring, just to confirm that it all works, the shifter and dash gear selector illuminates properly, and I don't get the "Hot Oil" error (which means the CANBUS wires aren't correct). With a successful test, I now need to go back through, solder and heat shrink the connections, then tuck everything away.

 

[pc1p]

I went back and cleaned up all the wiring for the transmission and shifter. I ended up using a small aluminum plate under the glove box to hold a small Painless 3-circuit (2 IGN/1 Hot) fuse box and relay, as well as the OBD-II Data Link port (this is used ONLY for the trans):

The angle of the photo here makes it look blocked, but I can easily access the purple 3A fuse for the relay "trigger" circuit (which is tied to the TIPM via an "add a fuse" tap):

With everything soldered and wrapped, I confirmed that the dash still lights up like it should (the only time you WANT to see all your dash lights on!):

...and the shifter correctly shows "Park":

I was at the point where I wanted to confirm that the various CANBUS connections were working as they should, so I cranked the engine to see if the starter would engage. This worked as it should, so I cranked it a few times throughout the afternoon to get some oil up through the system and into the valvetrain:

I also tested out the RPM Extreme Fan Controller to make sure it was working as it should via the 12v+ "optional override". I simply connected this to the battery with an alligator test clip, but it appears to be ramping up exactly as it should. I will be able to do the full test once the engine is running, but the fact that it is running and ramping properly so far is a good sign.

The JSS Trans Cooler mounts have arrived, as has the Hayden 689 Plate Cooler and a bunch of AN hose and fittings. Time to knock this out so I can fill with ZF fluid and then finally connect the lower radiator hose and fill with antifreeze (leaving the lower hose disconnected seems like it will make it easier to work on these trans cooler lines).

Remaining "To Dos" before first test fire:
- Hook up the radiator hoses; fill with antifreeze,
- Find a coolant overflow tank that will work and then install
- Install and connect trans cooler, fill with ZF Trans fluid
- Get the broken rear sway bar bolts out of the frame
- Test fit the Motobilt Rear Fuel Tank and skid
- Bring MB skid to powder coater
- Install MB tank and skid; reinstall rear bumper
- Run new fuel and EVAP lines
- Bolt the t-case back up and install the driveshafts
- Rough install exhaust downpipes (full install after first fire up!)