Trick Control Arms From Currie

Not often, but Currie Enterprises' new Currectrac adjustable upper control arms for cars with factory-equipped four-link rear suspension are a revolutionary twist on an old idea.

Adjustable upper control arms for GM A- and G-bodies and Fox Mustangs have been around for a while, and they allow easy dialing in of pinion angle in a four-link equipped car. The best adjustable uppers are double-adjustable, meaning one side does not need to be disconnected to change the length. Like many others on the market, Currie's new offering features a double-adjustable nut (with left- and right-hand threads, much like a turnbuckle), allowing you to adjust pinion angle with both uppers in place.

But what makes the Currie units truly revolutionary is the type of bushing used to cushion the shocks and rattles transmitted from the rear suspension members to the chassis and to provide articulation. On most traditional aftermarket uppers, polyurethane bushings are used to firm up the rear suspension. However, many experts argue that rigid polyurethane bushings exacerbate the tendency of these types of four-link suspensions to bind up under extreme travel. With conventional urethane types, rotation around the pivot point is accommodated by the bushing, but they will bind if there is angular motion. This can lead to creaking, control arms and brackets twisting, and in extreme cases even a wheel lifting off the ground. That's why many race-oriented rear-control arms are built with spherical rod ends, which allow the rear suspension to travel more freely through its range of movement without binding. However, there are tradeoffs. Rod ends don't have bushings to cushion the shock, and they are brutal on the street.

Here's where the new Currie arms get really trick--they feature a unique Johnny Joint bushing (named for John Currie) developed for off-road use where extreme articulation is a must. The Johnny Joint combines the ride-insulating qualities of a conventional urethane bushing with the motion of a rod end. In Ray Currie's words, you get the "articulation without flex."

The Johnny Joint was originally developed by Currie Enterprises for off-road vehicle use and is best described as a cross between a rod end and a conventional urethane bushing. Johnny joints provide rotation up to 30 degrees from the centerline of the pivot in any direction, similar to a rod end, with the added benefit of increased comfort and decreased noise and harshness. It's the best of both worlds.

Currie's beautifully designed and built adjustable upper control arms feature double-adjusting nuts, allowing them to be shortened or lengthened without removing the arm from either attaching point, saving much labor and grief.

The Johnny Joint was originally developed by Currie Enterprises for off-road vehicle use and is best described as a cross between a rod end and a conventional urethane bushing. Johnny joints provide rotation up to 30 degrees from the centerline of the pivot in any direction, similar to a rod end, with the added benefit of increased comfort and decreased noise and harshness. It's the best of both worlds.