The Definitive Guide to Truck and Car Rocker Panels

What Are Rocker Panels?

A rocker panel is the metal strip running along the bottom edge of your vehicle's body, located right between the front and rear wheel wells, directly below the doors. While they may appear to be just another part of your truck or SUV's exterior, rocker panels play a significant role in a vehicle's structural integrity.

Rocker panels are typically part of the body shell and are formed from stamped steel. On unibody vehicles, they’re welded directly to the frame, making them a permanent part of the vehicle’s lower structure. On a body-on-frame application, they’re an integral part of the cab, adding significant rigidity and strength.

Where Is a Rocker Panel Located on a Car?

Rocker panels are located just below the door sills, extending along the sides of the vehicle between the front and rear tires. If you open your door and look straight down at the edge where the body meets the underside, you're looking at the rocker.

Rocker panels can be visible or partially hidden depending on your truck’s design, trim level, or whether it’s equipped with factory step rails or side skirts. Regardless of how they’re styled, their location exposes them to some of the worst abuse from the road—water, corrosive salt, kicked-up gravel, and more.

What Do Rocker Panels Do?

Rocker panels serve two crucial purposes:

• Structural Support: On modern vehicles—especially those with unibody designs—the rocker panel plays a crucial role in overall rigidity. It helps prevent flexing in the body, especially during impacts. On trucks with body-on-frame construction, they still reinforce the cab and help distribute stress evenly.

• Protection: Rocker panels also serve as a first line of defense against road debris. As rocks, mud, and salt are kicked up by the tires, rocker panels take the brunt of the impact, shielding more sensitive components tucked behind or beneath them.

Unfortunately, the exact location that makes them protective also makes them vulnerable—which is why corrosion is such a common issue.

Why Do Rocker Panels Rust Out So Easily?

Rocker panels are one of the most exposed areas of your vehicle’s body—unfortunately, that makes them a prime target for rust. Here’s why they tend to rot out faster than just about anything else on your truck or SUV:

Constant Beratement by the Elements

Rocker panels sit low on the body. Every time you drive through a puddle, bomb down a gravel road, or blast through snow and slush, your rocker panels take a beating from whatever your tires kick up. Water, salt, road grime, and debris all accumulate here and begin to wreak havoc on the paint and underlying metal. 

Poor Drainage

Many rocker panels are hollow, forming enclosed cavities that can collect moisture over time. If drainage holes become clogged, water and road salt can sit inside the panel with nowhere to go. This trapped moisture quietly eats away at the metal from the inside out. If you can see rust on the outside, there’s likely a whole lot more within. 

Salt Exposure

For drivers in colder climates, road salt is one of the biggest threats to a vehicle’s structural integrity. Salt accelerates the oxidation process, making it easier for rust to develop and corrode ferrous metals. Rocker panels, thanks to their low position and hollow construction, are one of the first places to suffer.

Paint and Coating Damage

Minor chips or scratches in the paint—caused by kicked-up rocks or debris—can expose bare metal. Once exposed, moisture and air don’t take long to begin corroding the surface. Even a minor nick can develop into a significant rust spot without touch-up or protection.

Rocker Panel Types: Slip-On vs. Weld-In

If your rocker panels have already fallen victim to rust, don’t fret—you have options. When it comes to replacement, there are two main routes—weld-in and slip-on rocker panels. Each has its pros and cons depending on your budget, tools, skill level, and long-term goals for the vehicle.

Weld-In Rocker Panels

Weld-in rocker panels are just what they sound like—full replacement panels that are welded directly to the body after the rusted sections are cut out. This is the more permanent, factory-style repair that, if done correctly, can appear as if the rockers were never touched. 

Slip-On Rocker Panels

Slip-on rocker panels are slightly oversized, allowing them to slide over the existing rocker.  Typically fastened using adhesive, screws, or rivets, they’re a popular option for DIY-ers looking for a quicker, less invasive fix that doesn’t require access to a welder. 

How To Install Rocker Panels

Installing replacement rocker panels isn’t necessarily a weekend job—but it is manageable with the right tools, prep, and expectations. Whether you’re going the weld-in or slip-on route, the key is proper preparation and rust removal before anything new goes on.

Weld-In Installation

Weld-in rocker panel installation is more intensive and often done in a garage or body shop. The process involves cutting out the rusted sections, carefully fitting the new panels, and then welding them into place. After that, it’s all about grinding them smooth, seam sealing, priming, and painting to ensure the repair blends flawlessly with the existing body lines and paintwork.

This option is best suited if you have severe rot, want to fully restore the vehicle's structural integrity, or plan to keep it long-term. It’s the most durable solution—but it does require welding equipment, bodywork knowledge, and considerable time and effort.

Slip-On Installation

Installing slip-on rocker panels is a more DIY-friendly process. Instead of cutting out the old rocker completely, you typically grind down surface rust, treat any remaining corrosion, and fit the slip-on panel over the existing metal. These panels are typically attached using automotive-grade adhesive, rivets, or screws, and can be sealed and painted afterward to enhance durability and appearance.

It’s not a structural repair, but it’s a solid way to cover cosmetic damage, keep moisture out, and make your vehicle look a whole lot better—without breaking the bank.

Protect Your Rocker Panels with Rocker Guards

Whether your rocker panels are brand new or freshly repaired, the best time to protect them is before road salt, gravel, and moisture wreak havoc on your truck. 

That’s where aftermarket rocker panel covers—like Husky Liners Trail Armor rocker panels, RealTruck Bushwacker Trail Armor rocker panels, and  ICI Stainless Steel rocker panels—come in. 

These body protection accessories are made from durable, impact-resistant materials, like stainless steel and thermoplastic, and are custom-molded for a precise fit. They’re designed to shield your vehicle’s most vulnerable lower panels from everything the road throws at them, acting as a rugged barrier between your paint and the elements. 

Best of all, they are easily installed with 3M automotive-grade adhesive—no drilling or cutting is required. They’re a clean, quick upgrade that adds protection and a subtle, factory-style finish in minutes.

Whether you're trying to preserve your new truck or extend the life of your daily driver, Rocker panel covers from RealTruck are one of the most effective additions to your truck or SUV.