Building the full size SCX10XJ: Part 1

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Words: Scott G

When setting out to build a trail worthy rig, so many things go through your mind. What do you expect from the rig? What do you plan to do with it? What budget do you have to work with? These are all extremely important things to consider when selecting the donor vehicle. However, just know that no matter what you plan for, there will be extras needed, to include the expectations, plans, and budget. Building a 4×4 vehicle to go deep into the elements is not an easy task, and like most things in life, you get what you pay for. This means you have to outfit your choice with the best components available within your budget that will allow you to attain your goals.

This is not at all unlike developing the new SCX10, as all of the same parameters are considered, to include performance expectations and budget restraints. Not budget restraints for development, but budget restraints of our fans and customers. We often read the forums and see what people would like to see in the Axial vehicles. We are forced to make some difficult decisions when finalizing the package, as we want to include the world with these rigs, but also don’t want to ask for $699 for an RTR to get in the game. It is like that with all Axial products, so we do our best to aim for the sweet spot, enough features to perform at the top level, with a reasonable price tag. This is not an easy task. We are faced with the same decisions when building a full size rig. Do we want a supercharged V8, 1000 minimum on the RTI ramp, seating for 4, bulletproof axles? Of course we do, but the budget doesn’t allow for all of them, so we settle for what we can and have a blast doing it.

One of the most common things we read is…. “Oh no, not another Jeep vehicle”, well, I am here to tell you that most of us are Jeep people, so get over it. The Jeep brand is synonymous with the art of back country exploration with extreme reliability, exactly what we strive for with our little brand. It is a perfect marriage and we are happy.

When looking into new options for the new SCX10, we did what all outdoor enthusiasts do, we went into the woods to think about it, to do a little research. We were checking out all the rigs out on the trail and noticed that the XJ was a very popular rig for the most hardcore wheeler and for family back road exploration. We saw XJ’s that were exo-caged on 40′s all the way to bone stock 4×4′s loaded with the whole family and dog. This platform was exactly what we were looking for. It is one of the most popular 4×4 vehicles ever built, with millions of them on the road. Some say that Jeep actually invented the SUV with this release. It was not adapted right away for off-road use, as the old guard (Read: Wrangler, CJ5 and CJ7 owners) looked down upon these Jeeps, calling them cars with big tires, and promptly showing their owners the direction toward the nearest shopping mall or soccer field.

Some XJ inspiration we found on YouTube…

I personally had this experience with my 1993 Jeep grand Cherokee, I was given directions to the soccer field, immediately preceding my climbing an extremely nasty Granite rock face on Los Coyotes Indian reservation back in 1996. The CJ owners immediately began to bicker and argue that the other should climb it. Neither one did, nor did they express themselves again to me on the trail. They learned that day that a Unitized chassis wasn’t the end of the world, and that coil springs are like magic. The Cherokee (XJ) shared the same front suspension with the ZJ, though the XJ had leaf springs in the back, something the Jeep guys were used to back then. Any of the XJ’s and ZJ’s on the trail were hand built, as there were very few aftermarket components available with the exception of suspension which was primarily available to fit larger tires. We told some of our JK friends about our XJ desires and they immediately started flowing some memes our way, most of which we cant publish, but here are a few gems that made us laugh…

xjs

Thanks for the support guys…sheesh.

Fast forward 20 years, and these old grocery getters, mall crawlers or soccer field shuttlers are now extremely common to find on the trail. The off-road community has more than accepted them and many aftermarket companies now make a decent living supporting them. The hard part, finding a clean one-owner version with no rust and low miles, kind of like finding a Unicorn. One of Axial’s more predominant partners, Currie Enterprises, was at the forefront of developing suspension for these rigs so that they could be raced in a desert series called Jeep Speed back in the day. We consulted the Currie family and were introduced to Matt Chapman, the owner of the Cherokee that we based our SCX10XJ off of. As we have done in the past, we like to build the full size version of our scale rigs (see here…) to go out and experience what they can do, and stay on the forefront with regards to what the community is doing. At this time, Matt’s Cherokee was bone stock, as it had just been purchased and not modified yet. We elected to team with Matt and the Currie’s in effort to help develop the Full size XJ into an awesome trail machine all the while developing and testing our SCX10 II in tandem.

Here is a shot of Matt’s XJ when he got it, no rust with 150K miles…

After a good amount of research, we started to compile a list of necessities. We knew the rig had to be able to go with 4 door JK’s on 37′s, as most of Matt’s friends were rolling newer JK’s. We needed at least 35″ tires. Fitting 35′s under the Cherokee would require some proper fender flares and keeps the cops in Moab at bay. Notch Customs said “35″ tires with a 4″ lift, some welding required”. Currie makes a great suspension system for the XJ as well as their bulletproof Rock Jock 44 axles, and you know we love the performance of Icon Shocks. So, what we really needed was some armor. We looked long and hard at so many companies making XJ parts, and there is some awesome stuff out there. Russ at Notch Customs introduced us to JCR Off-Road, who ended up having one of the most complete armor systems available. Then we needed some lighting, the natural choice was Rigid powered by sPOD. Almost forgot wheels and tires. In effort to make the full size version look more like the RC, we elected to run a 35X12.50X17 BFG KO2 All Terrain wrapped around Method Mesh wheels. The 17″ wheel looks closer to a 1.9 than a 15″ wheel. Of course we needed some nice tone out of the 4.0 straight 6, so the XJ would need a Magnaflow exhaust. We had some details to sort but the main wish list was assembled!

First things first, the rig had to be made as reliable as possible by going through everything mechanical. We changed all the fluids, belts, hoses, pretty much everything we could to ensure reliability.

So, building a full size rig is just like building a scaler, get the base kit, then select all the options you wish to install. Here is our list!

2000 Jeep Cherokee XJ Parts list:
Currie Rock Jock 44 front high pinion axle with 4:56 gears
Currie Rock Jock 44 rear axle with 4:56 gears
Currie Rock Jock 4.5″ suspension system
Currie Antirock Sway bar system
EATON E-Locker rear, Detroit Locker front
JCR Vanguard Front winch bumper – No stinger
JCR Rear Bumper – tire carrier ready
JCR XJ Classic sliders
JCR Transfer case skid plate
JCR Gas tank skid plate
JCR Adventure roof rack
Notch Customs fender flares
Rigid 50″ E-Series LED bar
Rigid Dually x2 (front and rear bumper)
PSC Ram assist kit – steering
ICON Vehicle Dynamics 2.0 Aluminum shocks
Magnaflow exhaust
sPOD – Source with Bluetooth control
17X9 Method Wheels – Mesh (5)
35X12.50X17 BFGoodrick KO2 All Terrain tires (5)

Before we started the build process, Jamie Seymour, Axial’s R&D Industrial Designer and resident rendering expert whipped up this drawing for us to envision the build…

Stay tuned as we add more of this story in the coming weeks……

Axial “SCX10JK” – Icon Vehicle Dynamics Suspension

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We have officially placed the Axial 2012 Jeep Rubicon Unlimited “SCX10JK” in the capable hands of Rebel Off Road for them to start the build. The first thing on the to do list was a proper suspension system. We have had Icon Vehicle Dynamics as one of our marketing partners for quite some time now, and have decided to run their “Jeep JK 4.5″ complete suspension system” found here. We are also working with Dylan Evans, their head engineer to further test their new compression clicker reservoir shocks on our JK, talk about some incredible shocks, we can’t wait to run these on the trail! I personally have worked with Dylan for many years on different motorsport projects, and am really excited to see these guys working together on this. I am confident that this suspension system will suit our needs and surpass our expectations. Dylan is a mastermind at tuning shock and spring combinations for the best of both worlds, day to day driving, as well as a healthy dose of off-road abuse. Take a look at this suspension system as we break down the different components, and what purpose they will serve.

The new Icon Suspension System consists of:
Upper and lower front links
Upper and lower rear links
Front and rear springs
Front and rear pan hard bars
Front and rear pan hard brackets
Front lower shock mounts
Front reservoir mounts
Front and rear bump stop spacers
Extended sway bar links
Front and rear 2.5″ body Compression Clicker Reservoir shocks

Here is a shot of the entire system laid out on the Rebel shop floor..

With the Axial SCX10JK up on the rack, it is time to get to work and tear it apart..

The suspension links have a brilliant design. First off we have some race car parts with these huge heim joints, because strength is paramount in any suspension system. Second, Icon have developed a 2 stage threaded adjustment system. This means you simply place the link in place on the vehicle, then you adjust the length to desired spec, then tighten down. No more of this remove the link, adjust it, then replace it. It makes setting the caster on solid axle vehicle as easy as it gets!

The links themselves are designed for maximum flex. Pictured here are stock links with Icon links. You can see that the flex for the stock arm is meant to come from flex in the bushings and the arm itself. The Icon arm, has a race spec heim on one end and a Johnny Joint style joint on the other, meaning that the link is allowed to articulate throughout its range of motion without any resistance from rubber or torsional twist from the arm.

The front upper arms are designed to flex from one side and solid mount to flexible bushings in the Axle housing, these solid mounts have also been beefed up significantly.

The front and rear Icon springs are quite a bit taller than the stock springs, and should provide plenty of extra ground clearance, as well as the perfect rate once the vehicle is outfitted for battle.

The pan hard or “track” bars from Icon feature a much stronger and lighter tubular design. The ends of the Icon bars are equipped with heims or Urethane bushings which is a significant upgrade from stock.

The shocks for this project are probably the most striking change from stock. It is hard to imagine running on stock shocks after seeing these 2.5″ reservoir bad boys from Icon….
Rear Shocks

Front Shock

The install of the suspension system goes really smooth, at least that is what the staff at Rebel makes it look like.
Here is the front suspension before and after Icon links.

The front springs and shocks are huge!!

The compression clickers on the reservoir are going to be awesome, we cant wait!

The lower shock mount moves the shock out for clearance during full articulation.

And pictured with the reservoir mount in place, almost ready to rock!

The rear suspension was next on the list.
In stock form…

With the Icon links…..

Rear sway bar links

Rear springs and shocks

Completed rear suspension

The suspension stage of this project is only the beginning, be sure to check back in the coming weeks to see this vehicle coming together. We intend to build a proper Jeep JK with the highest quality products and then take it out and hit the trails. For the history on how this vehicle came about please check out our earlier blog postings here….
The Full Size Connection

Axial 2012 Jeep Wrangler Rubicon Unlimited

Axial Visits Rebel Off Road

To learn more about Icon Vehicle Dynamics and see some more of their high end suspension components be sure to visit their website here.

Add 4 Wheel Steering to Your Wraith

One modification that I wanted to make to the Wraith kit build I did here on the blog is 4 wheel steering. Driving a rig with four wheel steering is extremely fun, especially on a scaler that will see a lot of technical terrain. So, I recently gathered all the parts I would need to make this mod. In this article I will cover the parts used and give a few tips for making this conversion as simple as possible. Let’s get started……

Parts list for 4ws conversion:

AX80073 – AR60 OCP Steering Linkage

AX30777 – AR60 OCP Servo Plate

AX30078 – Zero Ackerman Steering Plates

AX30780 – Wraith CVD’s

AX30760 – XR10 Aluminum Knuckles

AX30762 – XR10 Aluminum C-hubs

AX30450 – Steel Flange Pipes

AX80072 – Servo Post Parts Tree

AX30524 – Grey 91mm links

AXA1221 – 5x11mm Bearings

AXA1230 – 5x15mm Bearings

AXA1417 – Grey 5mm spacer for steering

AXA1428 – Grey 55mm standoff

AXA1331 – Steel Flanged Balls

AXA465 – M3x10mm Self tapping Flathead screws

AXA434 – M3x8mm Self tapping Buttonhead screws

AXA119 – M3x20mm Buttonhead screws

AXA115 – M3x10mm Buttonhead Screws (x3)

A few photos of the major parts required:

Steering linkage

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Steering plates for knuckles

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Servo plate

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Aluminum knuckles

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CVD’s

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Aluminum C-hubs

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Steel flange pipes

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Steel flanged balls

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Before we get started there are a couple things I need to mention. One, I stretched the wheelbase of this Wraith already by replacing the stock rear lower links with our XR10 94mm lower links. This moved the rear axle back just over 6mm, or about a 1/4″. To extend the upper links to match the newly lengthened lowers, I used our long curved XR10 rod ends at the chassis instead of the short curved rod ends. You can see the new lowers and longer rod ends on the uppers in this photo.

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Another mod I made was to flip the plastic rear upper shock mount/chassis cross member upside down. This lowered the rear of my Wraith a little, which lowers the overall center of gravity. I also added a grey 55mm threaded standoff between the shock mounts for a little extra beef. I will explain why in a minute.

wraith-kit-463

One thing I notice right away when I tried to mock the rear servo up, is the lack of uptravel in the suspension due to the servo case hitting the bottom of the tube chassis. The servo case hits the chassis almost immediately when you try to cycle the suspension. To fix this I removed the rear plastic lower chassis brace and replaced it with one of our 91mm grey lower links from the SCX10′s. I bolted the 91mm link into place where the widest part of the lower chassis brace normally sits. You could also cut the stock plastic chassis brace, and just use the long section to tie the 2 halves of the tube frame together. The aluminum link will provide a lot more rigidity though, so I went that route. Here you can see the brace I removed.

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Look carefully and you can see the new 91mm link just below the upper links in this photo. Adding that 91mm link and the 55mm standoff between the shock mounts seems to replace any lost structural integrity from removing the stock rear lower chassis brace.

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After the lower rear chassis brace is removed/replaced you can mount the servo plate to the rear axle and attach the steering servo. I am using Futaba’s S9157 servos for steering duties on both axles. Here is a shot of my rear servo and servo plate before installation. I used the short self tapping M3x8mm buttonhead screws to attach the servo tabs to the servo plate. I will use the M3x10mm self tapping flathead screws to tie the servo plate to the axle. Then, I will use the M3x10mm buttonhead screws to attach the servo to the tabs.

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If you haven’t already, remove the rear wheels, drive hexes and cross pins. Next remove the rear plastic straight axle lockouts, and inner axle shafts. In order to remove the inner axle shafts, you will need to remove one of the screws holding the lower link/shock mounts in order to get the inner axles out of the housing. Replace the straight axles with the new CVD’s, attach the C-hubs to the axle, install the bearings into your steering knuckles, bolt the steering plates onto the knuckles using four of the M3x10mm buttonhead screws, insert the flange pipes into the knuckles and slide them into place over the C-hubs. Secure the knuckles to the C-hubs with four more M3x10mm screws. Then re-install the cross pins and drive hexes. Next we can install the rear steering link. One thing you will notice is the steering link has to be run upside down to clear the differential cover. Not a big deal, but you will need to drill the existing .100 diameter hole in the tie rod that the drag link secures too, all the way through the linkage. Then use one of the 5mm spacers between the drag link and tie rod with the long M3x20mm buttonhead screw to tie everything together. I will eventually trim the plastic boss hanging below the steering linkage, I left it there for now so people can visually see what I am talking about.

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A shot with everything buttoned up and ready to roll. Don’t forget to re-install the M3 screws you removed to get the rear axle shafts out too.

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Here you can see at full compression of the rear suspension, the servo sits perfectly in the rear cargo area without any interference from the chassis. Since I stretched the wheelbase a little, I did have to trim the cage a little where the plastic chassis brace attaches to the back of the tube frame. If you are still running the stock rear upper and lower links this shouldn’t be an issue.

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One last adjustment I made was to zero out the caster angle in the rear steer to make life on the rear servo a little easier. To do this I added a 3mm grey spacer (Part# AXA1415) to the lower links at the rear axle.

wraith-kit-483a

It is hard to see in this photo, but the rear steering kingpins are now perpendicular to the bench my Wraith is sitting on. This means the caster is set to zero degrees. Adding positive or negative caster will put more stress on the rear servo, and it will struggle to center itself in hard binds.

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Overall stance now…..

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One thing to keep in mind when adding rear steer to any vehicle, you may need to add a Castle BEC to your system, depending on the torque rating on the servos you use they may overload whatever ESC you are running. I am sporting a Tekin RS Pro ESC, Tekin 10.5t motor, Thunder Power 5300mah 2S lipo and dual Futaba S9157 servos. To my surprise after driving for a few hours with this set-up, the ESC was only overloaded a few times while trying to throttle out of a bind and steering with both axles simultaneously. I am going to try and gear my Wraith down a little to help alleviate that issue. But, in order to have smooth performance at all times installing a BEC is the only way to go.

Another thing to keep in mind is you will need at least a 3 channel radio, with a 3 position 3rd channel switch, to have independent control of your front and rear steering set-ups. I am using my Futaba 4PK radio with my Wraith. The 4PK allows me to set the rear steer up for 5 positions, center, 50% right, 50% left, 100% right and 100% left. Some radios will only allow you to steer the rear from center to full throw left or right. Only a dual stick radio will give you full proportional control of both steering set-ups. Now, you can run a 4ws set-up on a 2 channel radio as well, if you use a Y-harness to plug the servos in to work together. But, that set-up will give you 4ws all the time, there is no way to control the servos separately. Just a few things to keep in mind before you dive into converting your Wraith to 4 wheel steer.