Straight-axle 4x4 guys call them steering knuckles. Pavement racers call them uprights. Desert-bound off-roaders bounce the terms knuckle, upright, and spindle around fairly interchangeably. Who's right? With the English language being the flexible thing that it is, there's room for each of these terms. At the same time, "knuckle" is the most technically correct. Why? The purest definition of spindle identifies the protrusion around which the wheel and wheel bearings rotate. Spindles may be bolted to the knuckles or may be welded on. Spindles may be part of a unit-bearing wheel hub that doesn't directly attach to the knuckle at all. The term "spindle" can be interpreted several different ways, so we'll stick with "knuckle" for the sake of continuity. Fair enough?
What we're talking about is the part of the front suspension - truck or buggy - that directly connects to the suspension links, A-arm or I-beam, and the steering tie rods.
The knuckle is an oft-forgotten item, concealed behind the spinning aluminum grandeur of a high-performance wheel. Knuckles are often ignored until they scream for attention - usually by breaking. Fortunately, today's off-roader has a lot to choose from. Whether it's reinforced stock to completely fabricated, there's no reason to feel stuck with an OE part when building your desert ride.
To find out more, we took a road trip. SoCal has a plethora of knuckle builders, and we were able to call on four makers of durable, high-zoot knuckles.
Our one-day road trip started with Camburg Engineering in Huntington Beach, California. Camburg's palette is a diversified one, purveying everything from full-truck builds to seats to off-road lights, but there's no mistaking its heavy emphasis on high-performance off-road suspension systems. Camburg's '05 Ranger Edge worked well enough that owners Jerry Zaiden and Jason Campbell decided to pit it against full-on Trophy Trucks in the 2006 SCORE Baja 500. (The Edge has since changed hands and is now campaigned by Marc Burnett in the Best in the Desert series.) Camburg is now in the design stages of a new Trophy Truck. Called Kinetik, the Camburg Trophy Truck will be available turn-key, ready to take on the likes of Porter Race Cars and Geiser Brothers.
We then headed to Corona, California, to check out Total Chaos Fabrication's offerings. There's no mistaking the emphasis on quality and durability in the T.C. suspension lineup. T.C. is resilient, bouncing back into the ring after a devastating fire gutted its shop several months ago. If you've followed the MDR exploits of Dan Vance and Matt Helton and their respective Class 1450 championships, you've seen Total Chaos's bolt-on Toyota suspension kits in action.
The next stop was Kartek Off-Road, also in Corona. Kartek is nothing short of a high-end off-road candy store. Need full-on Class 1 or Trophy Truck parts? Need a weld-on tab, an oil cooler, or a suspension limit strap for your prerunner? Kartek has it all. Kartek's line of Pro-Am components includes a line of knuckle kits for A-arm prerunners, Class 1 buggies, and 2WD I-beam applications.
The day's final destination was the high-desert home of C&D Fabworks in Hesperia, California. Chris Wrublevski and Danny Guernsey have cultivated a reputation for high-end builds and reasonable prices. Matt Towery's '07 Class 8 F-150 (see "Standard of Excellence" in our July '07 issue), Steve Herrera's '69 F-100 (re: "Retro Rocket," June '05), and Battle At Primm-winning '86 Ranger are all examples of envy-inspiring C&D builds. While there's no question we're enamored with C&D's custom trucks, during this trip our lenses were pointed squarely at C&D's I-beam knuckles.
There was no question that knuckles are just as cool as high-end wheels and CNC-machined shocks. They might be less visible, but they're no less important.
 Here is a stock knuckle from...  Here is a stock knuckle from a Ford Dana 44 Twin Traction Beam system. These knuckles have been used on 2WD applications as well, sans 4WD drivetrain parts. The hollow, bolt-on spindle is stronger and holds bigger bearings than its 2WD counterpart. If you're building a 2WD I-beam truck, this is probably your best low-buck bet for a sturdy knuckle. |  Here's a stock '05-and-newer...  Here's a stock '05-and-newer six-lug Toyota Tacoma knuckle next to a fabricated model from Camburg. Even though Toyota saw fit to use durable forged steel, the Camburg knuckle is still stronger by virtue of bigger dimensions and boxed construction. Camburg begins with a precision-machined block that accepts the unit-bearing wheel hub and brake caliper, and adds plate to complete the knuckle. At the top, there's a machined insert for a Camburg uniball upper control arm mounting bolt. The Camburg knuckle re-locates the hub center to coincide with the lower ball joint, providing a 4-inch lift. Relocated lower control arms are not required. The resulting lift gives better ground clearance in deep two-track roads, and moves the tires away from the fenders. It is important to note that this type of lift knuckle cannot be used with 4WD because the relocated hub center is right where the CV joint goes. |  Normally powder-coated grey,...  Normally powder-coated grey, a Camburg Ranger lift knuckle looks great in the raw, too. This lift knuckle is for the Ranger Edge models and is designed for use with a uniball upper control arm and a pair of rod-end tie rods. Stock Ranger wheel hubs are used with this knuckle. |