Expedition JK Build

[JPK]

JPK made a great point about overlanding and rock crawling being at opposite ends of the spectrum. He also added some great points about weight, except I think that just adding lift and springs does not necessarily mean you can safely increase the payload.

The factory maximum payload is a combination of factors including the suspension, axles, tires, frame, brake system, cooling system, and transmission and probably some I'm leaving out. You can't just add springs and call it done. Can you squeak by? Probably, but not if you stay overloaded full time. You might end up hurting someone in a wreck. The ultimate worst case is you hit a school bus and they weigh your rig and it's massively overloaded - well then it's off to prison for you, but that's definitely a worst case scenario and I'm just throwing it out there to show that this is serious business. Just hurting someone is enough to deter me from overloading. I at least try to stay close to the maximum and it's a constant battle.

Also, if you add a roof top tent AND roll bars, you're changing the center of gravity in a big way and increasing your rollover potential.

The factory payload number for the Jeep Unlimited JK is 1056 lbs - that's passengers, gear and all modifications.

Some rough math works out like this...

roof rack 90 lbs
roll bars 100 lbs
hilift jack 39 lbs
engel fridge 53 lbs
dual battery 50 lbs
15 gal water 125 lbs
roof top tent 100 lbs
bumpers and winch 200lbs
armor 100 lbs
passengers 300 lbs

The above adds up to 1157 so we're already 100 pounds over and we haven't even added in any camping gear like cooking gear, chairs, sleeping bags, food, beverages, or recovery gear like chains, shackles, etc.

Rock Crawling and overlanding aren't at opposite ends! Stock is as far from rock crawling as overlanding, imo. Maybe think triangle?

For a better guide to the JKU's capability, I think looking at European towing specs might provide some insight. They are much greater than US specs from what I've read, but the Jeep is the same except wrt the transmission and in the case of the diesel the motor too. I think the JKU makes a good platform, but needs improvements to go either rock crawler or overland or mixed use between the two.

For the US Jeep, the axles (Rubicon D44's,) frame and even stock tires are no issue. The axle tubes and C's may benefit from some gussetting though. The ball joints should be watched and replaced with all steel when they go wobbly.

Auto Jeeps need transmission coolers for anything but street duty, but the transmission comes from a nine passenger minivan so should be weight worthy - turn off the O/D. The six speed? You would hope its up to it if its up to rock crawling, and it is proven for that, even with heavy armored rock crawlers.

A Hemi conversion fixes any transmission issues (replaced with a 5-45rfe which is a truck transmission) and cooling issues if done right with trans cooler and big aluminum cooler.

A better and all aluminum radiator might be a good idea for the stock 3.8, Griffin makes one, and there are some aftermarket fan improvements available. AEV's heat reduction hood really works and I've read that River Raider's scoop and vent ducted hood works too. Might want to go with a snorkle if for no other reason than it being the ultimate cold air intake.

I had thought the brakes would be an issue, but they have proven to be fine with 37', heavy loads even with an unbraked ~2000lb trailer behind. I found a one ton brake conversion and a couple of other brake beef up replacement options for the JK, but ended up happy with the stock brakes. Might face more frequent pad replacement though.

As far as the suspension, you can't just replace the springs, you need to go the whole route and fix oem steering and body roll issues imo. The AEV Premium kits do that.

As a model that sticks with the 3.8l, maybe Overland Journal's white AEV converted Jeep is a good model.

JPK

 

[Brigitta]

We both rock crawl and overland.

As JK popularity boomed the original admin for JKOwners couldn't put the time into it so he sold it to pirate4x4. pirate moved there JK stuff to JKOwners.com.

You need to set up your rig to suit your needs not to what others feel your rig should be.

I would steer away from a roof top tent if you really love exploring. Having to fold up your tent and put your stuff away everytime you want to drive is kind of a pain. It's much easier to pack a tent or tow a trailer and establish a base camp. Of course for this doesn't work if you plan on only spending one night in each location, but most folks I know set up a base camp.

We run 35's with beadlocks which works great on the rocks and fantastic in sandy washes. I wouldn't be off road without the beadlocks.

As for onboard air we run a powertank for speed and the ability to run power tools with a small back up compressor.

As for a roof rack and ladder, if you don't need it, skip the extra weight. The JKU has a ton of interior space and if you don't need the 2nd row seats, take them out. Kilby and poly performance make "floor systems" that give you a flat floor where the 2nd row was and it includes access to the foot wells for storage. We have a roof rack the we only run if we've got the whole family (5+75lb dog) on a hardcore technical multiday trail. Otherwise we fit everything inside. We have both interior and exterior jamboree racks.

Upgraded bumpers are a must as is something beefier than the Rubicon Rails. With the long wheelbase of the JKU we opted for poly performance's boatsides. They give protection in the rocks and you can pivot on them for tighter turns. They are HEAVY so keep that in mind.

Dual batteries are a good investment, as for the fridge, fantastic for long trips out in the outback, but pricey and bulky for the amount of fridge space you get. It's on my long term list but as long as I have to feed 3 teenagers, it's going to have to wait. We freeze all possible foods we pack which makes our cooler stay plenty cold on multiday trips.

Rotopax are cool but very pricey and don't hold too much water. Traditional jerry cans with spigots have worked better for us.

Lot's of computer programs for GPS if you want to use a satellite card and laptop, off road racers use the Lowrance Baja HD but they stopped making those and they are pricey. We run a Garmin Rino 530. Small hand held with topo and GMRS radio that is suction cupped to the windshield. Frankly, GPS is nice but off road it isn't that useful. Traditional maps are more accurate and will keep you off closed roads much better than the computer topo's. If you must have GPS, buying the Mopar HU with navigation and swapping it into the JK may be enough.

Just my 2 cents

 

[OverlandChronicles]

We are working our JK build plan also. I have learned a lot from this forum and some of my decisions on our TJ build I would not do again.

As mentioned in previous posts we are going to stay as close to stock as possible on a JK Rubicon.

2" lift with load-carrying springs - lower lift less strain on drive shaft etc, better on road manners to get us farther from home to start the fun stuff (4" on the TJ was overkill IMO)

33s - less weight and better mpg then 35s (have 33s on the TJ and its amazing what it will drive over)

Front and rear bumpers -w- winch, tow points, gear/light mounts etc

Heat reduction hood (possible snorkel at later date)

Will beat the factory skids - upgrade when necessary

Line-X the interior

That is all I am planing as the base.
The rest of the build will be lighting, storage, safety, recovery, comfort and navigation. Will be pulling the M-416 for larger items like a RTT.

 

[MuleShoer]

My JKU & Why

Maybe the description of my mods & why will help:
I started with a 2007 JKU X that I bought basicly wholesale with 39,000 miles on it. Today I probally start with a Rubicon and avoid some mods.
Suspension: I went with OME springs and shocks sized for increased load ie winch and bumpers, I also dropped the rear sway bar to compensate for increased ride height. No change to upper/lowers or steering. Jeep rides and tracks great. However I can see some short comings to these changes and will probally upgrade to and AEV approach down next year before my western trip.
Bumpers/Rock Sliders: I went with ARB front & rear & side, I wanted to retain the airbag function. They are fine not too heavy. Downside is rear bumper does not offer a tire carrier.
Winch: Warn 9000i with synthetic rope & a 60 inch HiLift jack
Differentials/Axles: Rear has an ARB airlocker, 4:88 gears & Superior evolution Axles, Splines are stock 30 spline. Front is the Dana 30 Ihve C-gussets reinforced and a long side truss welded in, again ARB airlocker, 4:88 gears & Superior Evolution Axles, Splines are stock 27 spline. I actually had a Dana 44 housing that after measuring size I decided to just keep the D30 plus I do most of my own work and beefing up he D30 cost me on my time. Both Diff covers are armored. When the ball joints go (any day now) I will try the new poly joints.
Wheels/Tires: AEV pintlers with 315-75X17 Duratracs, I got the wheels used.
Lights: IPF Driving lights upfront and IPF backup light rear. ARB gave me the driving lights otherwise I would have gone with Hella, they were the best value in th OJ equipment comaprison
Top/Rack: Went with a WildBoar Fast Back..Why? Momma said to. Also went with a WildBoar rack, nice rack...it is now forsale in the equipment section
Interior Mods: Dash mounts for Garmin GPS and Netboob with mapping program. Maybe next year I will switch to a touch pad
Storage: 5 containers for "stuff" like tools and recovery gear adding interior rack above storage containers
Engine/Transmission: Added trans cooler from B&M, AEV Snorkle, Dual batteries, ARB air compressor and programmer. Future plans are to replace the V6 & transmission with a 5.7 V8 hemi and 545 trans. IMHO the V8 is very stout coupled with the 545. you cannot do much with the V6. I looked at a good blueprinting but it is pouring good money down the rat hole.

Originally I was going to build a stand alone rig with RTT, frig ,draws, etc. But then I bought a Conqueror Compact trailer:wings:. All camping gear is with the trailer kit and my rig carries the necessary tools and parts to explore safely and get back to camp or be safe if stuck some where.
I can wheel most places they way it is and disconnet the sway bars for more articulation if needed. My approach to wheeling is more strategic, age does that to you. This is my semi daily driver when not driving the Cummins which happens to be in a dodge.

I feel naked now:Wow1:

 

[sgt rock]

Top/Rack: Went with a WildBoar Fast Back..Why? Momma said to. Also went with a WildBoar rack, nice rack...it is now forsale in the equipment section

:

did you have any movement when driving with the wild boar?

 

[MuleShoer]

did you have any movement when driving with the wild boar?

No movement. If you have a slight out of balance issue will acsent the vibration..good old harmonics. the rack is not that heavy, I could take the basket by myself and the frame can be carried by one person

 

[Topo.Ranger]

Thanks everyone for the input on this JK build! It has given me some stuff to think about! I have went against my natural instinct and I plan to get the aluminum body armor. I know there is still much more to plan out before this project is complete. During my recent port call to Dubai, I have noticed a lot of common things that is used out here in the desert.

I still like the fact of not having a trailer but it would be cool to have a base camp. I don't ever plan to stay in one place for more than 2 nights so it would be very convenient to get a trailer. Which leads me into another project. All the trailers that I have seen for sale are VERY expensive. I would love to get my hands on a M416 trailer. I have a couple drawings of a design that is similar to the military 1/4 ton trailer. Its more beefy at a little bit bigger but its got all I would need built into it. Its going to be a long project but I am willing to do it! I just need to get off deployment!

If anyone has pictures or ideas to help me out with the project I would appreciate it alot!!


And thanks again for the pointers!!