Rod End
What it does: Due to their high degree of rotation, spherical rod ends are often used on link ends and track bars in suspension systems that are designed for above average suspension articulation. There are a wide range of strengths and sizes available. The Ballistic Fabrication (www.ballisticfabrication.com) rod ends shown here are on Dustin Chernoh’s heavily modified ’83 Jeep CJ-8 Scrambler that we featured in the March 2011 issue of Four Wheeler.
What can go wrong: Spherical rod ends are not rebuildable and they do wear out, so it’s best to carry spares. They also transmit shock and vibration more than a rubber, polyurethane, or flex joint, so they may not be the best choice for a daily driver.
Shock Absorber
What it does: Shock absorbers control the rate of suspension movement in response to bumps. They also help to reduce roll and sway when accelerating, cornering, or braking. Without shocks, your rig would bounce after driving over uneven terrain until the energy was dissipated from the springs. There are a number of types of shocks, and some, like race-ready multi-tube bypass shocks and MetalCloak’s 6Pak shocks (www.metalcloak.com) are high-tech units that feature mega-adjustability and/or long-travel. Most 4x4s are fitted with monotube or twin-tube units. Pictured here is one of the Bilstein 5160 (www.bilsteinus.com) remote-reservoir shocks installed on our Dodge Power Wagon.
What can go wrong: Like any mechanical part, a shock can wear out with age. Sometimes the shock shaft will become pitted causing a leak, while other times it could be overheating, poor suspension geometry, or trail damage (like a bent shaft or damaged body) that will kill it. When most shocks wear out they are just disposed of. Basic shocks can’t handle being cycled for long periods of time over rough terrain. When this happens the oil inside the shock foams and the performance of the shock dwindles. This is why many wheelers choose to run race-style reservoir shocks. These shocks have an external reservoir and this configuration allows the shock to run cooler. An added benefit is that many of these types of shocks are rebuildable. Long-travel shocks are used in conjunction with long-travel suspension systems to maximize wheeltravel. Sometimes the failure isn’t the shock, but rather the shock mounts. The mounts can be damaged by an improper length shock, poor grade hardware, overextension of the suspension, or a missing bumpstop. If a shock mount breaks, the result will be a non-functional shock that will flop around on the other mount possibly causing damage to the remaining mount or the rig.
Suspension Joint
What it does: These rebuildable joints, often called flex joints, are typically used on the ends of link arms. They offer a good range of motion so they work well with flexy suspensions and they isolate shock and vibration well so they’re daily driver-friendly. An example of a rebuildable suspension joint is the Rough Country X-Flex Joint (www.roughcountry.com), shown here.
What can go wrong: Typically, these joints need to be maintained (greased) often, so if you have to factor that into your maintenance routine. And they will wear faster than a rubber or polyurethane bushing, so plan on rebuilding them every so often.
Sway Bar
What it does: A sway bar helps to control body roll, thus making your rig handle better. It does this by connecting a metal bar to each side of the suspension. This bar distributes the force from one side of the body to the other.
What can go wrong: By its very design the sway bar inhibits suspension travel. This is why the off-road aftermarket has created sway bar disconnects, which allow the sway bar to be detached from the suspension off-road so the travel can increase. There are many disconnects available and include those from JKS (www.jksmfg.com) and TeraFlex (www.teraflex.biz). Not only does a sway bar impede travel, we’ve seen sway bar end links break during wheeling where the suspension was cycled to its maximum. Manufacturers such as Dodge/Ram and Jeep have devised ways to detach the sway bar from inside the cab. Our ’05 Dodge Power Wagon has a pushbutton-operated sway bar disconnect (pictured) that disengages the sway bar and allows the suspension to flex to its fullest.
Torque Arm
What it does: Also called a traction bar or anti-wrap bar, this component helps combat axlewrap in leaf spring-equipped rigs. Axlewrap can happen during maneuvers such as hard acceleration or climbing a steep obstacle. What is happening is that the leaf springs are contorting into an “S” shape, and typically the result is that the axle moves up and down rapidly as the leaf springs twist and recoil in an attempt to maintain their intended shape. This is hard on the springs as well as the rear drivetrain. A torque arm has one end mounted to the axle and another to the frame and is designed to keep axlewrap from happening.
What can go wrong: A torque arm can impede suspension travel. Arms designed specifically for off-road travel will include a flexy joint or rod end so it flexes along with the suspension. Some torque arms hang low and can decrease ground clearance. If your rig sees a lot of off-road time, a system like WFO Concepts (www.wfoconcepts.com) universal torque arm is worth a look because it’s designed to mount high and it comes equipped with high-quality QA1 rod ends.
Torsion Bar
What it does: Some IFS rigs are equipped with a torsion bar setup. Instead of using coil springs in some configurations, this system uses long steel bars that act as “springs.” The torsion bars typically slide into slots in the lower A-arms and into “keys” in a crossmember amidships. As the A-arms travel up and down this causes the bar to twist on its axis, which is resisted by the bars torsion resistance, hence a spring effect. In this photo you can see the lack of springs and the driver-side torsion bar is visible.
What can go wrong: Like any other spring, torsion bars can fatigue over time, especially if heavy components like a winch/bumper or plow is fastened to the front of the truck. In salty environments the torsion bars will rust to the control arms and keys, making removal very difficult. Some suspension lifts use crossmember drop brackets to keep the torsion bars properly aligned with the front suspension, but the downside to this is a loss of ground clearance. Finally, adjusting the stock torsion bar keys to create suspension lift decreases the amount of suspension downtravel.
Track Bar
What it does: Found mostly on coil-sprung, but also some leaf sprung, solid axle-equipped rigs, the track bar (also known as a panhard bar) locates the axle laterally. It allows the axle to travel up and down, but prohibits it from traveling from left to right. The track bar fastens to the vehicle frame on one end and to the axle on the other. When a rig is lifted, many aftermarket suspension companies include a track bar drop bracket to correct the track bar angle. Typically, an OE track bar will be fitted with a rubber bushing on at least one end. The track bar shown here is on a Dodge 2500 pickup truck.
What can go wrong: The rubber bushings can wear out over time, causing steering “slop.” Also, the factory track bar can limit wheeltravel. There are many aftermarket track bars available and most are beefier than stock and some are fitted with rod ends to improve suspension articulation. An example of a beefy, rod end-equipped track bar is the KORE Off-Road 3rd Gen track bar (www.koreraceshop.com) for 2003 through 2012 Dodge/Ram trucks.
U-bolt
What it does: There are typically two U-bolts used per side on a leaf spring-equipped, solid axle rig. The U-bolts provide the necessary force to clamp the axle, leaf springs, and lift blocks (if equipped) together.
What can go wrong: If U-bolts become loose the axle may shift, the ride height may change, or the axle pinion angle may change, resulting in driveshaft vibrations. In a worse case scenario there can be significant damage to the suspension and axle. Corrosion may also be a factor in salty environments. Regularly inspect and tighten the U-bolts, especially if you have added a lift and installed new U-bolts.