Pirate 4x4 banner

Urban Assault TJ Zombie Killer build.

120K views 205 replies 52 participants last post by  bugman114 
#1 ·
So we are going to start on the T-Rex Junior project. For the last 11 years we have beat on our old faithful Dodge T-Rex 6x6. It has been a great truck and we learned alot from it.







So now I an going to start on a much smaller project. I got a 98 TJ. First I put on some armor, bumper, winch, and then when I tried to get my family all in the Jeep I realized that I cant fit us and a lunch box. The T-Rex could fit 6 people and tons of extra stuff. So that is when I realized that I have to modify this TJ beyond the regular mods.

 
See less See more
3
#2 ·
So parts have been coming in, and It is getting exciting. I want to strech this jeep so that I con put two bench seats in the back with an optional machine gun ring in the roll cage for the optional 30cal, or 50 cal machine gun....you know for the Zombi Apocalypse...:rolleyes:




I want it much lighter that the T-Rex, and smaller an nimbler. It may not ba as capable as the T-Rex but it should be fun.

Tires came in, These Wranglers are great. only 35s..... and 7 of them to boot..

 
#4 ·
Thanks for the offer. I may need some bodies to help lift the Tub off later this week. That is the hard part. The fun will be streching the frame, and building the suspension.
 
#5 · (Edited)
So here is the official plan. This TJ will be streched to fit two more bench seats and hold a machine gun ring in the roll bar.

We will make it 6x6 just like the T-Rex, but we will not use Rockwells.

We will use regular axles in the rear that will be facing each other with a drop box in the middle.

The rear suspension will be a four link with air bags to create a true 'walking beam' suspension. Each side will be tied to gether, so when the middle axle gets pushed up it will put more air pressure on the rear axle behind it, forcing more traction.

The drop box will allow us to disengage the rear so that we can do front digs.

For now we will stick with the 4.0, but I have a v8 option.

Final it will be painted green, most likely lime green.:smokin:
 
#6 ·
Brackets from Ballistic Fabrication are almost all here, and I like thier Busings.

Things are getting cool:

The guys at Ventures Truck Parts here in Ogden UT have scored the coolest things. They bought hundreds of the these axles that were built by Dana for industrial / military purposes, yet they were never used. So they got these axles as brand new salvage.
The axles are Dana 60s that are lighter due to an axle tube that is not quite as big around as a regular Dana 60, they are only 60 inch wide (jeep width) and they have these monsterous axle shafts. 35 spline, then we add disk brakes, then detroit lockers. And their prices are really good.







Here are the lockers going together, Detroits in the Rear.





E-locker for the front which is going to be a high pinion 44.
4.56 gears all the way around. Pictures coming with the disk brakes on. We will use the standard TJ front brackets for the 44 up front, and I will fabricate the mounts for the two rear axles for the air bag suspension.



 
#8 ·
All the brackets and joints from Balistic Fabrication showed up and we are ready to start tacking things in place. So my budd Alex and I started the tear down of the Jeep.









It took us only 3.5 hours to tear this jeep down to the frame.

next we work on streching the frame.
 
#10 · (Edited)
In 1994, Kevin had a 6x6 CJ8 in the TTC. I've got some old photos. It used semi-truck-cab-airbags for the suspension, all hooked together. As one bag lifted, it pressurized the other bags, forcing them down. Worked great. This is before the modern link ends were readily available, so his arms were a little primative, but conceptially, it worked flawlessly. He should have won TTC, but had some fuel problems.

Kevin modified a Dana 18 and a Dana 20 transfer case, whereby he ended up with BOTH outputs, in the same case. So one output fed the near (mid) axle, facing forward. The other output fed the rearward axle, with a carrier bearing off the frame, to clear the nearest axle. In normal drive (2wd), both rear axles were under power. In 4 high, the front was then engaged, and in 4 low, it worked as OEM designed, except it fed power to both.

The CJ8, had a single enlarged rear opening, which looked factory. The only (future) problem would have been tire size, as his design was for 33 inch tires, hence the size of the wheel openings. As tires progressively got larger, his axles would have been too close together to go larger, and the wheel opening would have been too small..... Both easily fixed, but would require much bodywork. The wheelbase/body was definately stretched, and quite a bit too.

I've asked Atlas, a couple times, if they ever intended to build an offset case. Each time they've told me there isn't enough market demand. But I think someone could still modify a case, to run dual outputs, without tooooooooo much difficulty. There are some amazing fabricators/machinists here.

And one final comment, for now. You aren't going to be wanting to do any front digs, with this rig. With TWO rear axles, and FOUR rear tires, trying to drag this heavy, sticky, turd around with a D44 will be foolish. You are used to the invincibility of Rocks. You gotta relearn how to drive weak components.
 
#11 · (Edited)
Thanks tree climber, great input. A lot of people who have done the 6x6 conversion have done a dual output t-case with twins shafts going back and even a carry-over for the rear most axle. We are doing it similar to the prototype version. We are putting a drop box inbetween two dana 60s. the 60's will be facing eachother. Thus, we have only one output shaft coming out of the t-case and then it is split right between the two axles.

Yes our components are weaker than our old T-Rex's rockwell axles, but With Dana 60's and an built 44 we should be OK to do some digs in soft ground. We can shut off the rear, and brake the rear independantly. It will be fun to test out. By design I want my u-joints to be the weak link, cause those are easies and cheapest to fix if any part is going to grenade.

Also this Jeep is going to be more for moderate trail rides, we need the room for the whol family, dog, and camping gear thus the need to strech it.

Here is how we built our old Tow RIg that used to tow our green T-Rex around. 1998 Cummins Dodge 3500 We used a bolt on Gear Over Box, bolted to the middle axle and it sent the next shaft over its shoulder to the rear. This worked great!! We put 250K miles on this rig with only a crank sensor and clutches as maintenance replacements. Not to shabby. The company that makes the gear over box is reworking a next generation. Startracks custom RV is thier name, I think???







http://carphotos.cardomain.com/ride_images/3/590/2141/26473570002_large.jpg

 
#14 ·
I got hooked on 6x6 years ago whe I had a 6x6 Max AATV. My buddies had four wheelers and thew where alot faster, but when we came to this huge tree across the road they cound not get over it, and my 6x6 just crawled right over.

Then when I compared the T-Rex to even radically built fullsized 4x4 trucks the 6x6 could go tons more places than they could. At one 57% slick rock wall, I climbe right up it and no one could follow. You just have so much contact patch with 6x6, and there are less places to get hung up on. If you had 6x6 with six wheel steering that would be the best. 6x6 weakness is turning radius.

This should be a fun build. I should have the framed stretched by tomorrow night.
 
#21 ·
Today going to bring the axle back to our garage, and start welding up the Ballistic Fabrication Brackets and get them mounted on the axles. Airb bags should also arrive today or tomorrow. Mock up will happen this thursday.
 
#28 ·
Alex and I really wrangled with the Wrangler design. The plan was to set a drop box (out of a monster truck) in the middle of the two axles and a short drive shaft between the drop box and the axles. This would allow alot of articulation not having two drive shafts coming out of the transfer case and have to use a carrier baring to get the rear drive shaft all the way back. The we hit a snag. Tom Wood Woody's drive shafts) would have a difficult time matching our 14 spline 1480 yokes comming off of the Drop box. He then started talking about custom yokes and the $$$$$$$$$$$ went up way out of my budget. So I picked up a 205 to see if it would work inbetween the axles. It is much heavier and tons wider. The drop box is really narrow wo it would have bee a perfect fit. the 205 pushed the axles too far apart creating a breakover danger for the t-case, and tire scrub would be a huge issues. also it would make the jeep alittle longer than I would want. DANG I want this to be street legal so 6 wheel steering is not an option. So we will have to settle for alittle les articulation and more drive shaft, thus the 205 is going to be put after the t-case and we will have both axles facing forward and more drive shafts with a carrier to get the rear to the rear. Kinda your average 6x6 set up.

Last night we fabed the crossmember for the t-case and redesigned the suspension. First set back will be overcome.
 
#29 ·
Kind of sad to hear about the hiccup as I was really looking forward to seeing the "facing axles" design work...

Sounds kind of silly that they would have difficulty matching yokes... What about building flanges to allow practically any type of yoke? What about hybrid "*******" yokes where you machine the ears off one (to get the spline section) and maching the splines out of another (to get the proper u-joint ears) then press and pin and weld them? I've done it before to mate 22,000 LB Rockwell rear end driveline to a 205 yoke with GIANT drive in Spicer u-joints; 44" tractor tires and 400+ hp has yet to destroy the setup (and NO more u-joint failures!).

You mentioned walking beams as the suspension setup... What about cradling the transfer case in the walking beams and setting up the beam bushings in-line with the pinion yokes to eliminate almost any slip in the jack shafts and accomadate a super short jack shaft design? Maybe I've had too much coffee this morning and that only makes sense to me, but it almost seems like you could get away with the 205 that way and still keep a fairly short span between axles. It migh cause some crazy suspension issues though having the walking beam pivot that far away from the axle centerline, but depending on how you set up the walking beams, it might not be horrible...

I'll stop brain farting all over the computer now.

Awesome build! Keep up the great work!
 
#31 ·
Great ideas. The cost was one factor for abandoning the drop box, and if we used a 205 in the middle it would make the jeep too long. I only have two jeep bodies to work with and the 205 in the middle would put me past the sheet metal I have.

Thanks for the great input though.
 
#30 ·
I love the build, but the TJ frame is marginally strong enough for stock TJs, I use a frame jig to stretch TJs for a living and I would be very cautious to use the stock frame for what you are doing with it, they are weak by most light SUV standards, and flex with big tires and big lifts as they are. If you want more information, I can give it to you, just PM me your information and I will get in contact with you some things you might want to consider doing to help with the frame, and some things we do to help strengthen them. Again, I love the build, just dont want you to be disappointed with the end result....as I would have been on my first one.
 
#32 ·
Great advice. I am used to working with the Dodge frames which are pleanty stout. We have put that to the test with three rockwells under it and pleanty of pulling, rocks and torture.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top