Coil Spring / Shock Tower Brace / Trailing Arm / Panhard Rod Kit
What Are Coil Spring / Shock Tower Brace / Trailing Arm / Panhard Rod Kits?
A well-sorted rear suspension is one of the most meaningful upgrades you can make to a performance vehicle or off-road build — and few categories illustrate this better than combination coil spring, shock tower brace, trailing arm, and Panhard rod kits. Each component in this system plays a distinct and complementary role, working together to control how your axle moves relative to the chassis in every direction.
Coil springs serve as the primary cushion between the axle and the body, absorbing road impacts and supporting the vehicle's weight. Unlike leaf springs, coil springs are compact and compatible with a wide variety of suspension geometries, making them a popular choice for performance cars, muscle cars, and lifted trucks alike.
Trailing arms are horizontal links that mount forward of the rear axle and connect to the chassis or unibody via pivot joints. They are responsible for controlling the axle's longitudinal position — preventing it from walking forward or rearward under acceleration and braking loads. In live-axle setups, trailing arms work in tandem with a lateral locating device to give the axle full positional control.
That lateral locating device is typically the Panhard rod (also called a track bar or track rod). As a simple but highly effective suspension link, it runs sideways across the vehicle — connecting one end of the axle to the chassis on the opposite side — and prevents the axle from drifting side to side. Panhard rods are most commonly paired with coil spring suspensions, where a separate lateral link is required since the springs themselves do not resist lateral load.
Rounding out the kit, a shock tower brace ties the suspension mounting points together, stiffening the chassis and reducing flex under cornering and high-load conditions. By triangulating the shock towers, these braces ensure that your carefully tuned suspension geometry stays consistent when it matters most.
Purchasing these components as a coordinated kit — rather than sourcing each piece independently — ensures proper fitment and geometric compatibility. Kits are engineered so that spring rates, arm geometry, and lateral location all work together for predictable handling, improved traction, and reduced axle hop.
Who Makes These Kits?
BMR Suspension is a well-respected name among muscle car and performance enthusiasts, known for engineering precision suspension components specifically for American rear-wheel-drive platforms. Their coil spring and rear suspension kits are designed to tighten up factory suspension geometry for improved handling on the street and strip.
For off-road and Jeep-focused builds, Artec Industries brings heavy-duty fabrication expertise to suspension kits that are built to handle demanding terrain. Their products are designed with real-world durability in mind, making them a go-to choice for builders who push their rigs hard on the trail.
What to Consider When Shopping
- Vehicle application: These kits are highly vehicle-specific. Confirm fitment to your exact year, make, and model before purchasing.
- Intended use: Street performance, drag racing, and off-road applications all have different geometry and spring rate requirements.
- Material and construction: Look for kits using DOM or chromoly tubing, high-strength hardware, and polyurethane or spherical rod-end bushings for longevity.
- Adjustability: Adjustable trailing arms and Panhard rods allow you to fine-tune pinion angle and axle centerline position — especially important after a lift or lowering modification.
- Complete vs. component kits: A full kit simplifies the upgrade process by ensuring all pieces are designed to work together, eliminating guesswork in fitment and geometry.