Rocker Panel
The structural panel that runs below your doors between the front and rear wheel openings. Think of it as the car's waistline—critical for strength, prone to rust, and expensive to fix when it fails.
What 'Rocker Panel' Actually Means
Rocker panels (also called "rockers") are the vertical panels you see when you open the door and look down. They run the full length of the car on both sides, connecting the front and rear sections of the body structure.
Classic Mustangs have a two-layer rocker panel design: - Outer rocker panel - The visible panel you can see and touch - Inner rocker panel - The hidden structural piece inside
The space between these two layers is a rust magnet. Water and dirt enter through drain holes (or where drain holes used to be before they clogged 40 years ago), and the metal rusts from the inside out.
Here's the problem: you can't see most of the damage until it's severe. The outer panel might look fine while the inner structure is rotted through. I've seen rockers that looked solid until someone leaned against the car and put their elbow through the metal.
Why It Matters for Your Mustang
Rocker panels are structural members that:
- Support the door openings - Keep doors aligned and prevent sagging
- Connect front and rear body sections - Maintain overall body rigidity
- Handle stress from jacking - Jacking on a rotted rocker can collapse it
- Contribute to crash protection - Side-impact strength comes from rocker structure
When rockers fail, doors don't close properly (gaps or resistance), body flex increases (squeaks, rattles, panel cracks), floor pans lose support at the edges, and subframe connectors (if installed) can pull away.
Pull up the carpet at the door sills. Look for rust staining, soft spots, or visible holes. If the outer rocker has rust bubbles or holes, the inner structure is worse.
Replacing a rocker panel involves removing outer trim and moldings, cutting out the old rocker panel (outer, and inner if needed), inspecting and repairing adjacent areas (floor pan edges, torque boxes), fitting and tack-welding new rocker panels, stitch-welding panels to avoid heat warping, grinding welds smooth, applying body filler and block sanding, priming and painting, and reinstalling trim.
This is not a weekend DIY job unless you have metal fabrication experience and a welder.
Cost Impact
| Repair Type | Typical Cost (LA) | Labor Hours |
|---|---|---|
| Small outer patch section | $400–$1,200 | 4–10 hours |
| Outer rocker replacement (one side) | $1,200–$2,800 | 12–24 hours |
| Full rocker (outer + inner, one side) | $2,000–$4,500 | 20–40 hours |
| Both rockers (full replacement) | $4,000–$9,000 | 40–80 hours |
*LA labor rates: $110–$120/hour. Parts cost: $150–$400 per side for reproduction rocker panels (outer). Inner rockers add $200–$350 per side. The labor is what kills you—removing the old rocker, fitting the new one, welding it properly, finishing the body work, and painting takes time.
Ask me how I know these numbers.
Common Issues
Rust Jacking
Rust expanding between inner and outer panels, forcing them apart
Clogged Drain Holes
Water trapped inside accelerates corrosion
Floor Pan Extension Rust
Rockers rot where they meet floor pan edges
Previous "Repairs"
Fiberglass or bondo over holes (fails quickly)
Jacking Damage
Collapsed rockers from jacking on rusted metal
See This in Action
- Mustang Rust Repair Cost Guide: LA Labor Rates and Timeline Reality
Complete rocker panel repair breakdowns, inspection techniques, and real shop estimates
- Pre-Purchase Mustang Inspection Checklist
Learn how to spot rocker panel rust before signing the title
Want to Learn More?
Download the Mustang Restoration Starter Kit (LA Edition) for:
- Complete terminology reference guide
- Cost estimation worksheets
- Pre-purchase inspection checklist
- Shop interview questions
- Project timeline planning tools
No upsells. No bait-and-switch. Just the information Dorian wishes he'd had before he bought his first project car.