Shackles? All those do is connect the springs to the frame. What sort of innovation can there be related to shackles? This is a valid question. Shackles are the least glamorous component of a leaf-spring suspension, but they can still have a large effect on suspension travel and ride quality.
As a leaf spring travels through its range of motion, the effective length of the spring changes. A highly arched spring will gain length as it compresses, whereas a completely flat spring will effectively get shorter as the spring both compresses and extends. If the shackles are not properly engineered to accommodate this range of motion, they will bottom out, resulting in a harsh ride and poor handling.
In recent years, options beyond the factory stamped steel have emerged that have the potential to provide everything from increased travel to improved ride to more precise handling. What follows are some of the common (and not-so-common) aftermarket shackle options.
All-Pro offers replacement shackle hangers that incorporate a Johnny Joint for additional flex and less spring fatigue. These work in conjunction with All-Pro's zinc-plated steel shackles that feature greasable bushings. The mounts must be welded to the frame, making them the perfect addition when you need to change your shackle mounts to accommodate longer leaf springs.
Con-Ferr is one of the oldest names in lift shackles, offering applications for nearly every truck on the market for 40 years. All shackles are manufactured from 3/8-inch steel and gold zinc-plated for instant recognition. The shackles feature a jig-welded center brace for increased strength and stability, and are available in a variety of lengths and widths.
Currie offers a wide variety of shackles for Jeep CJs, YJs, and XJs. The towbar shackles incorporate an extra mounting pin to allow Currie's towbar to be attached to the shackle. This is perfect for vehicles with tubular front bumpers that do not contain a flat mounting surface for traditional towbar mounts. The quick-release pins allow you to easily remove the towbar when you get to your destination. All Currie shackles are constructed from 1/4-inch steel and feature greasable polyurethane bushings and a bolt-in center brace to offer improved stability.
Nth Degree Mobility's Zig-Zag hangers get rid of the rear shackles on your CJ or YJ altogether. After a rear spring becomes totally unloaded, it can fall away at the shackle end because there is no direct connection where the shackle had been. The amount of separation is limited only by your shocks and springs. At the same time, the product actually increases the side-to-side stiffness of your suspension for better handling: Since the spring ends are connected to each other and the frame by the Zig-Zag assembly, they cannot twist due to cornering loads on pavement.