4130 Upper Control Arms - Dirt King DK-812993

For 2003–2024 Toyota 4Runner / 2007–2014 FJ Cruiser / 2003–2023 Lexus GX470 & GX460

Built to Solve Real Problems. Designed for Real Off-Roaders.

If you drive a 4Runner, FJ Cruiser, or Lexus GX and are ready to step up your suspension performance, the Dirt King 4130 Upper Control Arms are built for you. Developed to fix the issues we’ve all faced — squeaky bushings, high-maintenance joints, and geometry thrown off by lifts — these UCAs redefine reliability, handling, and ride quality both on and off the trail.

Whether you’re overlanding, rock crawling, or commuting, these arms perform flawlessly. Crafted from precision-welded 4130 chromoly tubing, they feature maintenance-free SilentSpin™ hybrid bushings and heavy-duty Probearing Pro 4 ball joints with 76° of articulation for smooth, controlled steering. Sealed against dust and debris, they maintain perfect alignment from 0–3" of lift, while delivering an extra inch of down travel when paired with Dirt King, King, Fox, Icon, or other aftermarket coilovers.

⚙️ Key Features

• 🧱 4130 Chromoly Construction – Precision-welded for unmatched strength, rigidity, and long-term reliability.

• 🔩 Pro 4 Series Ball Joints – Forged SAE4140 housings with 76° articulation and hardened ball studs for exceptional durability.

• 💧 SilentSpin™ Hybrid Bushings – Maintenance-free and greaseless, engineered for quiet articulation and zero squeaks.

• ⚙️ Geometry Corrected Design – Optimized caster and pivot angles for precise alignment and improved control up to 3” of lift.

• 🧰 Fully Rebuildable – Every wear item is serviceable or replaceable for lifetime use.

• 🔒 Corrosion-Resistant Finish – Zinc-plated hardware and black powder coat for protection in all conditions.

• ⚡ Preassembled for Fast Installation – Ships ready to bolt on — no guesswork required.

• 🇺🇸 Proudly Made in the USA – Built and tested for the most demanding off-road environments.

🧾 Specifications

📦 What’s Included

• (2) 4130 Chromoly Upper Control Arms

• Probearing SilentSpin™ Bushings

• Heavy-Duty Probearing Ball Joints

• Ball Joint Caps

• Upper Control Arm Bolts

• Dirt King Sticker Pack

🧩 Features at a Glance

• CAD-designed for precise suspension geometry

• Maintenance-free SilentSpin™ bushings — no grease, no noise

• Corrected caster and pivot angles for lifted applications

• 76° ball-joint articulation for maximum movement

• Fully rebuildable, corrosion-resistant construction

• Preassembled and ready to install

• Made and tested in the USA

🚙 Vehicle Compatibility

Designed for OEM and Dirt King components. Compatibility with other brands must be confirmed with the manufacturer.