Vehicle Fitment

• 2015-2023 Ford Mustang (S550 Chassis — All Trims including GT, EcoBoost, V6, Mach 1)

Fitment Notes

• Compatible with all S550 Mustang models — GT, EcoBoost, V6, Mach 1
• Does not fit Shelby GT350, GT350R, or GT500 — these applications require dedicated SPL RUA variants
• The inner bolt position is locked out to a single fixed position — all camber adjustment is performed at the knuckle end using the SPL Double Adjuster mechanism, eliminating the need to reach the difficult inboard adjustment point of the factory arm
• Rear wheel alignment required after installation
• Sold as a pair (left and right)
• Made in the USA

Features

• Wide-range rear camber adjustment — significantly greater adjustment range than the factory eccentric-bolt upper arm, allowing precise camber settings for both aggressive street alignment and maximum negative camber track setups without modifications to other suspension components
• SPL Double Adjuster mechanism at the knuckle end — relocates all adjustment to the outside of the arm for easy, accessible on-car alignment without special tools or difficult reach to the inboard mounting point
• Hardened PTFE (Teflon) lined rod ends — eliminate the bushing deflection of the factory rubber upper arm bushing that causes dynamic changes in camber under load; low-friction articulation does not significantly increase NVH relative to factory
• Hardened SPL Double Adjuster stud — purpose-designed for the S550 application; FEA-validated and destructively tested to confirm load capacity under the maximum lateral forces generated by the stickiest track tires
• 6061-T6 billet aluminium arm body — lightweight, corrosion-resistant, and rigidly constructed with sufficient clearance designed in to avoid contact with the axle and frame throughout the full range of suspension travel and adjustment
• Blue anodized titanium socket head cap screws — lightweight, corrosion-resistant fasteners for the adjustment mechanism
• Steel lockout washers — secure the inner mounting bolt at the fixed inboard position
• Grade 10.9 hex cap bolts with lock nuts — high-strength fasteners at mounting interfaces
• All wear components (rod ends) are user-replaceable — allows the arms to be rebuilt without replacing the entire assembly
• Designed with FEA (Finite Element Analysis) and destructively tested — SPL validates load capacity in-house using computational modelling and physical destructive testing before release
• Made in the USA

Specifications

• Part Type: Rear Upper Camber Arm Kit (Adjustable) — Pair
• Position: Rear upper arm (camber/wishbone arm)
• Arm Material: 6061-T6 billet aluminium (black anodized)
• Rod Ends: Hardened PTFE (Teflon) lined
• Adjuster: SPL hardened Double Adjuster (knuckle end)
• Inner Mount: Fixed lockout position (single bolt)
• Fasteners: Blue anodized titanium socket head cap screws; Grade 10.9 hex cap bolts with lock nuts; steel lockout washers
• Quantity: 2 (pair)
• Country of Manufacture: USA
• Warranty: 1 year (SPL PRO product warranty to original purchaser)

Included Components

• 2x Adjustable Rear Upper Camber Arms (left and right, 6061-T6 billet aluminium)
• 1x Hardware Kit (titanium socket head cap screws, Grade 10.9 hex cap bolts, lock nuts, steel lockout washers)
• 1x Installation Instructions

Product Description

The SPL Parts SPL RUA S550 is an adjustable rear upper camber arm kit for the 2015+ Ford Mustang S550, replacing the factory upper arm with a precision CNC-machined billet aluminium assembly that provides a significantly wider camber adjustment range and eliminates the bushing deflection of the OEM rubber-bushed arm. On the stock Mustang, the rear upper arm uses an eccentric bolt at the inboard mounting position for camber adjustment — the range is limited, the inboard mounting location is difficult to access, and the rubber bushings allow the arm to deflect under lateral load, causing dynamic camber changes during hard cornering that reduce grip consistency.

The SPL RUA S550 addresses all three issues. The inner bolt position is locked to a single fixed location — all adjustment is relocated to the knuckle end via SPL's Double Adjuster mechanism, which is accessible and fast to adjust with common hand tools without removing the arm. The PTFE-lined rod ends provide smooth, low-deflection articulation across the full range of rear suspension travel, holding the camber setting precisely under cornering loads. The design was developed using FEA modelling and verified through destructive physical testing to confirm the arm can withstand the extreme lateral loads generated by high-grip track tires on the S550 platform. All wear components (rod ends) are field-replaceable, allowing the arms to be rebuilt rather than replaced when service is needed.