The Shopping List (Part 1)

The Chassis and axles

The Microsoft Excel spreadsheet was long and full of goodies!  Better get out a towel, because you’ll probably be drooling in a minute.  Also, pull out a can of Red Bull as this list is long and you’ll need the energy to get through it!

Top on the list is a chassis from Blue Torch Fabworks.  It will be mostly 1 1/2” chromoly in .090 and .120 wall thickness and will be TIG welded for strength. Though this same chassis can be built of 1 ¾” just as easily, we decided that with the extra triangulation and chromo, we’ll take advantage of the small weight savings of stepping down a bit in tube diameter. Luckily, Dan and Bender are amazing with a TIG and the entire chassis was carefully laid out by Matt in SolidWorks.

Many of the mainframe tubes will be CNC bent ensuring perfection with each build or repair.  The chassis will be jig-assembled so every RockHer II chassis or repair tube that comes from BTF will be identical.  The wheelbase will be setup for 103” and the interior space will provide for 5” of clearance over Becca’s helmeted head.  She’s 5’, 8” for those trying to compare. 

The axle assemblies are the next step and one of the toughest decisions we’ve ever made.  We’ve been long-time fans of HEAVY Dana 60 axles…we beat our rigs so hard that we have remained absolutely sure that anything else would not hold up.  About a year ago, I saw a new part that I became curious about.  A post on the Pirate4x4.com forums discussed this new product that would change the face of the sport.  It was the first real high pinion 9” center section.  For those that don’t understand, we use high pinion differentials that raise the driveshafts up and out of harm’s way.  Until this differential came out, the only high pinion Ford 9” was really an 8.8” gear that is NOT strong enough to handle the shock loads we place upon them.  Looking further into it all, I found a couple guys out of Minnesota had found an extremely effective solution and they were calling it the “True Hi 9”.

Their third members use a very special gear set designed specifically for their carrier, are the only 9” pinion with three bearings to support the extreme loads, and are the only high pinion 9” centers that use “thrustblocks” to support the ring gear.  The Hi 9 Thrustblocks (patent pending) are an innovative idea to use an adjustable bolt to pre-load the side of the ring gear just opposite of where the pinion pushes on it.  This keeps gear deflection to a minimum, highly reducing the stresses that would destroy a normal 9” gear if it was used upside down in what’s known as “reverse rotation”.  When the True Hi 9’s came out, we were intrigued, but leery as these guys hadn’t had time to prove their designs.   Now, with a year’s experience under their belts, we decided it was time to take advantage of the higher clearance of a 9” housing, the lighter weight, and the quick-change capabilities of the gears and lockers built into the “drop-out” design third member used in Ford 9” housings.

We decided to go with their lowest gear ratio, which is 5.38, in order to attain the crawl ratio we need.  We need to note that not only is the True Hi 9 idea innovative, it also uses the best parts available for assembly.  You know what they say, “If it ain’t broke, don’t fix it!”  Well, Chris and Mike at Hi 9 knew that it would be tough to build better parts than many of the current ones they can buy and build into their great design.  Two of the companies they work with are Currie Enterprises and Randy’s Ring and Pinion. One of the critical pieces is the Currie Enterprises “Daytona” pinion supports...that’s the four bolt flange you see just under the yoke on 9” differentials that holds the outer pinion bearing in place. 

They get them from Currie and make a few tricky alterations for upside-down oiling, and then have complete faith in that part because we know the reputation of Currie and their vast experience of Ford 9” use in drag racing.  John Currie told me he thought the idea for the True Hi 9 was a good one and that he was happy to have his parts on such a good product.  The same went when I spoke to our great friend Mac at Randy’s Ring and Pinion.  He explained that Randy’s supplies many of the common components on the Hi 9’s.  Mac agreed with the Currie evaluation of the Hi 9 and was stoked to hear we would be giving them a try.  Mac and Randy’s Ring and Pinion sent over a number of parts for our diffs including set-up kits and the new line of Randy’s Forged 1350 pinion yokes for Ford 9”.  With all of the hits and stresses driveshaft yokes tend to take, we’ll be glad to have the forged yokes…obviously, we’re using the u-bolt style. 

For lockers, we chose to go all ARB.

We have always been a big fan of ARB and their selectable lockers and have never had a failure of a locker to date in 14 years of wheeling and competing.  With the RockHer II being our 8^th 4x4 with ARB’s, that solid performance makes it a no-brainer when choosing our lockers.  Also, there are many times in competition and on the trail where being unlocked is to your advantage.  Having the choice just makes it better, especially when you cannot run rear-steer in the class we’re building the RockHer II for.  I tell you, the tricks you can do with an unlocked ARB and cutting brakes are AMAZING.  Also, for the simplest things like driving on a leaning sidehill, unlock those ARB’s and you’ll find your rear end isn’t sliding downhill so badly.  An ARB isn’t just a part of your crawler, it’s a part of your strategy.

The axles and u-joints…you know it already…the same company that supplies the high majority of competition axles and hardcore u-joints also gets a call from us each time we’re building something new.

CTM and the company’s owner, Jack Graef, have the top reputation in the entire industry for quality and service.  He’s building us 300M 35-spline steering axles for the front and 35-spline full floater axles for the rear.  The axles and u-joint design allows us to turn 45 degrees with comfort and we’ve had ZERO issue with them in the many years we have run the Red Bull RockIt I and the Red Bull RockHer I.  If you’ve seen us wheel, you know the abuse those CTMs withstand! We’d like to thank Jack…“YARRGGGHHH!”

Sorry, if you’re a competitor from the west, you’ll understand…otherwise, don’t sweat it!

Holding all of these components together are the axle housings.  Another tough product decision was turned easy after speaking with Brian Ellinger of Diamond Axle.  He explained the process his company uses when creating their fabricated housings and the end result is basically stronger, more compact, and higher clearance than other axles on the market, especially the ones we’ve been using.  Another HUGE benefit is the weight savings over a Dana 60.  The housings shipped out with 3/8” wall DOM tubing at less than 90 lbs each.  Have you ever lifted a Dana 60 housing???  I swear those are over 160 lbs., probably more.  I wondered how they were built so strong and Brian explained that Diamond Axle actually double welds each panel joint (inside and outside) of the fully fabricated housing and they use a unique system to offer more support where the axle tubes enter the housing.  Putting all of that together, I asked him if we were sure it was the strongest it could be.  His answer was yes, it was the last housing we’d need to buy for this new crawler.  However, for “BLING” factor, he laughingly offered to make us a custom set of housings from chromoly…before he could tell me he was joking, I placed my order and now Brian’s wondering how in the world he got into this as the chromo housings are NOT something they would do as they are really overkill on an already overkill product…does that make it double overkill Brian???  The housings were ordered with the diffs offset FAR to the driver’s side and the final front wheeltrack being 80”wide and the rear 74”.  The Diamond Axle rear housing is setup with their thick flange for bolt-on Chevy spindles that match the front.

 The knuckles.  Here’s a change for us.  It is clear that the stock knuckles we used to use just don’t cut it any more.  Running big tires, super-strong steering systems, and turning as tight as we do, we require a knuckle that can withstand FAR more abuse than stock stuff could ever dream of.  That is where the Dedenbear Knuckles come in.  They are a kingpin design and are designed to be many times stronger than stock as well as being set up for our tight turns right out of the box. Dedenbear has built an amazing reputation over the years and due to their higher volumes of sales (a reflection of their parts and service) they are able to keep parts in stock by placing larger orders…when you need something they manufacture, it’s nice to know it’ll be on the shelf.  They’ll be bummed when we paint their trademark Orange knuckles blue, but everyone will still know we’re running Dedenbear when we take huge hits and rolls in stride, without destroying the knuckles.  To ensure the strength, we chose the Chevy-style Dana 60 knuckles with 5 bolt high steer arms.  We’ll actually fabricate those arms at Blue Torch, but the studs, knuckles, and forged inner “C’s” come straight from the same company we get our transmission cases from. One thing to note is we’re looking forward to having the steering stops cast right into the knuckle. We’ve bent plenty of the steering stop bolts on past rigs and it’ll be nice to have something stronger than a 3/8” bolt sticking out to keep the knuckles from over-turning.  Dedenbear was touting to us that all of their Dana 60 knuckle parts were interchangeable with stock parts.  I’m sure that’s nice for the budget builder, but for us, we’re going all the way on these parts.

The outer axle parts will be Chevy based and using the traditional spindle/wheelbearing type versus unit-bearings.  We’ve never had any issues and find them less expensive and easy to care for.  The brake calipers will be from a mid 80’s Chevy ½ ton and right now, we’re still shopping for pads that are stickier than the stock ones.  For the lug pattern, we’ll stick with our successful 5 on 5 ½ using the 5/8” studs and big 45 degree taper lugnuts.  They work great and we’ve never broken any studs.  We do have to sand the hub a bit though so we can fit the thin-wall 1” socket over the lugnut.  We just sand the area where the socket contacts, so it goes pretty quickly and does not steal much, if any, strength.

Drive flanges will be the ones that PolyPerformance made famous under their “pirate” themed flange covers.  On ours, Dave (PIG) will lovingly apply his cool version of the blue and silver Red Bull design you’ve seen on all of our rigs.  The drive slugs he has are chromoly and are bulletproof…no wait, that doesn’t even come close to describing their strength…they are DUSTIN-PROOF!

As The Poly Drive Flanges were backordered, we ran into a big stumbling block...on a build like this, those obstacles are dangerous.  One call to Rock and Roll OffRoad solved all of that and they sent us 4 of their super-bling driveflanges with the sexy girl logos on them.  We have to send them a huge thanks for stepping up and filling in temporarily and to give back to the Pirate board, we'll come up with some fun giveaway for hen we get the Red Bull Driveflanges.  Thanks in a big way to the crew at Rock and Roll OffRoad.

Wheels will be Pro Comp Alloys with custom beadlocks on them.  We prefer the Pro Comp rims because they have a more aggressive safety bead to keep the inner bead on stronger, and they are manufactured with a process called “pre-screened, low-pressure, counter-pressure, casting.”  Yes, they are a cast rim and not as strong as the rotary forged ones we use on the Red Bull RockIt, but in the years we have been running them, we’ve had nothing but great luck, especially considering how much abuse we put on them.

Our tires are also Pro Comp and they are the 37 x 13.5 x 17 X-Terrains with XCC (Extreme Competition Compound) super-sticky rubber that everyone calls so lovingly, “the cheater tires!”  This will be the first season Becca has run sticky tires and we feel the wait for Pro Comp to develop them will pay off as they have a compound that breaks in like no other.  After a few minutes of scuffing them, they develop thousands of tiny ridges running horizontally to the direction of travel.

You cannot believe how good these tires are and we’re excited to run them.  We normally run them at around 6 psi, but the lighter weight crawler may require a different pressure.

Speaking of weight, Becca’s current Pro Modified rockcrawler, the Red Bull RockHer I, weighs in at just over 4000 lbs.  The goal is to shed 800 lbs…that’ll be tough to do…I wonder if we can pull it off!

The steering will be a custom high-steer setup using BTF highsteer arms and a “Redneck Ram” hydro assist steering ram from West Texas OffRoad.  In years of using Matt’s rams and steering systems, we’ve had nothing but great luck and this time we expect it to be no different.  Bender has an idea to mount the ram from the axle directly to the highsteer arm, eliminating the linkage wear and tear, but we’ll just have to wait and see what he can pull off.  We will not order the ram from West Texas OffRoad until we have the linkage in place and the exact travel measured.  Matt’s rams have a chromoly body with a heavy wall to take serious abuse.  For our needs, he uses a ¾” shaft to get the right balance of speed and strength. We suspect the ram will be about 9” long to accomplish the 45 degrees of turn we are shooting for. 

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Blue Torch FabWorks, Inc

Red Bull RockCrawling Team

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