SuperPro Caster Correcting Radius Arm Kit – Left & Right Set | Built-In Caster Correction for Lifted 4WD Vehicles

Restore correct caster geometry and eliminate the steering instability caused by lifting your 4WD with the SuperPro Caster Correcting Radius Arm Kit — a complete left and right radius arm set with built-in caster correction engineered specifically for lifted vehicles. When you raise a 4WD, the factory radius arm geometry washes out caster angle — the rearward tilt of the steering axis that provides straight-line stability and self-centring steering feel. The result is vague, wandering steering that requires constant correction at highway speeds, reduced straight-line stability, and in some cases caster shimmy. The SuperPro kit solves this by building the caster correction directly into the radius arm geometry — no separate correction plates or adjusters required.

Caster Correction by Lift Height

• 50mm (2") Lift: ~4° of caster correction
• 75mm (3") Lift: ~2.5° of caster correction

Key Features

• Built-In Caster Correction – No Separate Adjusters Required: Caster correction is engineered directly into the radius arm geometry — the arm itself corrects the caster angle lost during lifting without requiring separate correction plates, offset bushings, or adjustable components. A cleaner, more robust solution than bolt-on correction accessories
• Restores Straight-Line Stability & Steering Precision: Correcting caster angle restores the self-centring steering feel and straight-line stability that is lost when a 4WD is lifted — eliminating the vague, wandering steering and constant correction required at highway speeds on lifted vehicles running factory radius arms
• Eliminates Caster Shimmy: Insufficient caster angle after lifting is a primary cause of caster shimmy — a resonant oscillation in the front steering that occurs at certain speeds. Restoring correct caster angle with the SuperPro kit eliminates this condition
• Complete Left & Right Set: Kit includes both left and right radius arms — a complete replacement set for both sides of the front axle
• SuperPro Quality: Manufactured by SuperPro — a respected suspension specialist known for high-quality polyurethane bushings and suspension components for 4WD and performance applications

Specifications

• Kit Contents: Left & Right Radius Arms (Complete Set)
• Caster Correction: ~4° at 50mm (2") lift / ~2.5° at 75mm (3") lift
• Application: Lifted 4WD Vehicles (verify fitment for your specific vehicle)
• Part Number: TRC1217
• UPC: 9317745816751

⚠️ Fitment Verification Required: Verify this kit is correct for your specific vehicle make, model, and year before ordering — radius arm kits are vehicle-specific. Wheel alignment required after installation — caster, camber, and toe must be set correctly after fitting new radius arms. Professional installation by a 4WD suspension specialist is strongly recommended. Confirm correct caster correction amount for your specific lift height before ordering.