LokJaw is staying 8-lug front and rear, which means the front suspension has to carry real truck hardware. The usual 5-lug ProSpindle setup is meant for lighter-duty applications, so it doesn’t match a heavy Duramax build running 8-lug hubs, large unit bearings, and 15-inch Wilwood brakes. The fix is a custom spindle built around the existing Roadster Shop geometry, while making room for the larger hub and brake package and managing the load those parts put into the spindle. That geometry matters. Kingpin inclination, wheel backspacing, and scrub radius all work together to determine steering effort and driving feel. Get the scrub radius closer to zero and the truck is easier to control. Push it the wrong way with the wrong hub and wheel relationship, and the tire gains leverage over the steering. The custom spindle design solves the packaging problem by using a machined, keyed assembly with more material where the loads are highest. The caliper bracket keys into the spindle instead of relying only on bolts, and the larger mounting surface helps transition braking and vehicle loads into the spindle more cleanly. That’s what it takes to keep an 8-lug truck honest when the front end has to match the weight, hub size, and brake capacity of the rest of the build.
This episode centers on a fabrication problem created by the truck's overall build direction. Banks already has Strange Engineering working on a custom eight-lug rear end for the Duramax-powered project, but the front suspension needs to match. Roadster Shop normally pairs its chassis with a Wilwood Pro Spindle, a five-lug cast-steel spindle intended for lighter-duty applications. That approach does not fit this truck, which uses heavy-duty eight-lug hubs and carries the weight of a diesel platform. The solution is to develop a custom front spindle that preserves Roadster Shop geometry while accepting the larger Duramax hardware and brake package.
The truck used for the visit is a 1966 Chevrolet C20 with an unusual backstory. One of the Truck Show Podcast listeners offered it to host LT for one dollar after listeners complained that he could not credibly co-host a truck podcast without owning a truck. His co-host Sean Holman put a dollar on the console, and the deal was done. The truck is rough, noisy, and clearly worn out, but it serves as the basis for the project and makes the trip to Kibbetech Off-Road under its own power, despite the usual old-truck drama involving fuel smell, starting quirks, and parts threatening to shake loose on the drive.
Before arriving at the shop, the team lays out the steering and suspension constraints that will govern the spindle design. Much of the geometry is already fixed by the Roadster Shop chassis, including kingpin inclination, which in this ball-joint suspension is defined by the imaginary line drawn through the upper and lower ball joints. Where that line meets the ground relative to the tire centerline determines scrub radius.
That scrub radius has a major effect on steering effort and feel. A small scrub radius gives the driver more control and reduces the leverage the tire has over the steering system. If the geometry approaches zero scrub radius, steering effort can become low enough that even a vehicle without power steering can remain manageable at parking-lot speeds, assuming the vehicle is light enough. By contrast, a large scrub radius, such as one created by excessive wheel spacers, gives the tire much more leverage over the steering and makes the vehicle harder to control. Wheel backspacing therefore becomes an important tuning variable. Roadster Shop has already established the inclination geometry, so the spindle and wheel package must be arranged to keep scrub radius as close to zero as practical, whether slightly positive or slightly negative, in order to improve steering feel.
At Kibbetech, the fabrication team explains how the custom spindle is being developed. Banks and Roadster Shop supplied the original Wilwood Pro Spindle geometry that the chassis was mocked up around, then asked Kibbetech to adapt that geometry to an eight-lug heavy-duty application. The new design uses Duramax two-wheel-drive unit bearings along with large Wilwood brakes: 15-inch rotors and six-piston calipers.
Rather than simply scaling up a conventional spindle, Kibbetech designed a modular fabricated spindle that preserves the original Pro Spindle geometry while accommodating the much larger hub and brake loads. The assembly is fully machined and keyed so the parts locate positively during assembly. That means the pieces can interlock, bolt together where appropriate, and then be welded without requiring a dedicated fixture. The spindle begins with a 1.25-inch-thick plate and incorporates a front snout block. Machined keys locate the caliper bracket, and the billet-aluminum radial-mount caliper adapter keys into the spindle itself so the bolts are not carrying the entire load by themselves.
Packaging is the main challenge. The brake package is very large, but the available ball-joint spread is relatively small. The lower and upper ball-joint spacing is about 13 inches, and much of that sits inside the rotor envelope. For comparison, Kibbetech notes that a typical long-travel setup might have roughly 20 inches between the upper and lower uniball centers while using a smaller 14-inch rotor. Here, the caliper remains comparable in size to what they use on off-road builds, but the rotor is larger and the suspension pickup spread is tighter. That forces the spindle to carry substantial braking and cornering loads in a compact area, so extra material has to be added to maintain strength.
The Duramax unit bearing itself is a major part of the strategy. It offers a much larger mounting surface than a traditional spindle snout arrangement, which improves how loads transition into the spindle. The bearing is designed for Chevrolet 2500 and 3500 trucks, including single-rear-wheel and dually applications, so it is inherently suited to high-capacity service. The version used here is a two-wheel-drive unit bearing, meaning it does not have the center bore and splines for a driven axle shaft.
A tour through the Kibbetech shop shows how these one-off and low-volume parts are produced. The spindle components are machined on a Haas VF-4SS vertical machining center, a three-axis mill. The main spindle block, which carries the upper and lower ball-joint mounts as well as the brake mount structure, is machined in two operations. One side is cut first, then the part is flipped onto a fixture plate so the opposite side can be machined.
The discussion also touches on practical machining considerations. When holding a block in a vise, the general rule is that more material engagement is better, but fabricators do not always have the luxury of large clamping margins. An eighth of an inch is described as a bare minimum, while the spindle blanks in this case have roughly a quarter to three-eighths of an inch of material held in the vise, which is enough to support aggressive cutting passes with good stability.
The visit also provides context by comparing the Banks truck to other Kibbetech builds. One fabricated chromoly plate lower control arm shown in the shop represents the kind of front suspension commonly seen on lowered trucks. In previous applications, Kibbetech has extracted about 21 inches of front-wheel travel from that style of setup. Another truck in the shop, referred to as the chrome truck, demonstrates the company's tendency toward highly finished fabrication, with polished transmission case surfaces, polished skid plates, and billet seat mounts and sliders.
The team also explains why silicon bronze is often used when tying a cage into a cab structure. Because silicon bronze melts at a slightly lower temperature than standard steel filler and has some flexibility, it can better tolerate movement in the surrounding sheetmetal without causing the panels or welds to crack.
A short-course rear suspension example shows how Kibbetech can package substantial travel while retaining more of the original truck body. That build achieves about 19 inches of rear travel while keeping a full bed, allowing room for practical cargo and a spare tire. The shop's in-house bulkhead assemblies, which combine billet and fabricated elements, are designed to fit a range of full-size trucks including Chevrolet and Toyota applications. In those systems, the lower control arms mount low in the bulkhead, while the upper suspension uses billet aluminum J-arms. The J-arm layout is chosen because two large King shocks must fit in the same area, and a conventional A-arm would interfere with the shock package and engine packaging.
The spindle discussion naturally leads into the hub and brake hardware used across different classes of trucks. For the Banks build, the front uses the same eight-on-180 bolt pattern found on the Duramax platform. Kibbetech notes that they are building other diesel prerunners as well, so retaining the eight-lug pattern is useful beyond this single project.
The rear hardware shown in the shop is much more extreme. One rear hub uses a 3.25-inch bearing and accepts a massive axle shaft of roughly 2.5 inches in diameter. These are Pro-Am trophy-truck-style hubs adapted from the more common six-on-6.5 off-road pattern to the larger eight-on-180 pattern needed for diesel builds. The comparison highlights the difference between production-based heavy-duty truck components and full race hardware. A complete set of the Pro-Am hubs, including rotors, rotor adapters, bearings, seals, and front and rear snouts, costs about $10,000. By contrast, the production-style Duramax unit bearings used on the Banks truck are ordinary service parts that can be sourced through normal aftermarket channels such as RockAuto.
In addition to the spindle package, Kibbetech recommends another signature component for the truck: the hydraulic handbrake they call the Hoon Handle. It has become a recurring feature on many of their builds. Although it is obviously useful for playful driving, they explain that it also has a practical off-road function. In dirt, a driver may not want to apply the main brakes aggressively because that can unload the rear of the truck and make it rotate too quickly. Using the handbrake can help settle the chassis and control the truck's attitude more precisely. With the custom Kibbetech spindles and Wilwood brake system already planned, the handbrake is presented as a fitting complement to the overall package.
By the end of the visit, the front-end plan is clear. The truck will retain Roadster Shop's intended suspension geometry, but the front spindle will be re-engineered as a compact, heavily reinforced fabricated assembly built around Duramax unit bearings and large Wilwood brakes. The design addresses steering feel through scrub-radius considerations, solves the packaging problem created by the large rotor and small ball-joint spread, and gives the heavy diesel truck a front end that matches the custom eight-lug rear.
The episode closes by teasing the next stage of the project, when Gale will explain the details of LockJaw's supercharged Duramax L5P and answer questions that have been building up around that powertrain combination.