Trail’s End: December 1996, A Pivot-In-The-Middle Chevy PickupPosted in Features on June 5, 2017
In the Dec. ’96 issue of Four Wheeler, we published a piece on the 30th Annual Sierra Trek. After an overview of the event we displayed a series of photos and information geared around “custom innovations” that we saw on attending 4x4s. The collection included a Toyota with a rear leaf spring/coil spring combination suspension, a rig with flatbed box tubing that held 12 gallons of compressed air, an early Toyota with an IROC Camaro 350ci V-8, and a squarebody Chevy with a pivoting frame.
The Chevy with the pivoting frame dominated the story. We wrote, “This Chevy gets radical flex with the help of a chopped and boxed frame fit with custom crossmembers and a pivot in the middle fabricated from two axlehousings. The pivot provides a reported 34 inches of wheel travel (not including the suspension), and the frame features a pin-locking system to hold it in place when pivoting is not desirable.
“Supplementing this Chevy’s 34 inches of wheel travel (43 degrees of pivot) is a 2-inch spring lift for improved approach/departure angles and a seldom-used ARB Air Locker in the rear. The vehicle crawls well over any terrain and an additional benefit is an ultra-smooth ride on dirt roads-none of the bone-jarring bumps are transmitted from the rear axle to the cab; the pivot helps disperse the energy straight up instead of up and forward.”
More information on the pivot system included this: “Coilover shocks mounted under the bed provide return-to-center functions, and the fuel, brake, and electrical lines run through the center of the pivot.”
It was noted in the story that the pivot idea was first formulated and implemented by a guy named Michael Olinger for use around his farm and had since been refined through research and experimentation. There were also a couple of cautionary statements regarding the fact that the pivot system was “Not an undertaking for most grassroots mechanics,” and “should not be attempted without thorough knowledge and expertise as to how to manufacture it…”
The story also noted that a patent was pending on the pivot system. Furthermore, the owners were looking for a manufacturer to help put the idea into production. We wrote, “They have the plans for a kit that’ll make retrofitting most pickups a cinch for qualified mechanics in a well-equipped shop.”
We don’t recall the pivot idea going into production, but it wasn’t the last time we saw a pivoting 4x4 in action. Wesley Wells’ “swiveling” ’69 M135A2 was the top vote-getter for the 2007 Top Truck Challenge and Warren Kreyer’s ’51 Dodge M37 was a competitor in the 2003 Top Truck Challenge. Warren’s Dodge used a custom-crafted frame and housing that allowed the rig to pivot in the middle, but it also had a hydraulic ram that attached to the assembly, which allowed him to force the pivoting process however he wished. Apparently the pivoting worked because Wesley’s rig tied for Fifth Place and Warren tied for Second Place respectively during competition, which were strong finishes.
In the big scheme of things, pivoting 4x4s are pretty rare. We haven’t seen any on the trail in a while, but if we do, you’ll be the first to know.