Cusco upper control Arm (P#: 965-474-L)
Cusco’s Adjustable Rear Upper Control Arm (Rear), is a bolt-on alignment component designed to add rear camber adjustability on the BRZ/86 platform—especially useful after lowering the car or changing wheel/tire fitment. It’s commonly listed for Subaru BRZ (2013–2021 ZC6, 2022+ ZD8) and the Toyota equivalents (FR-S/86 1st gen, GR86 2nd gen), making it a go-to option for owners who want more control over rear alignment than the factory arms allow.
The biggest advantage is straightforward: more alignment range and better control. The arm uses a turnbuckle-style adjuster with ±15 mm range, letting you add or reduce rear camber to match your setup. Many alignment-focused users like this because it can correct excessive negative camber from lowering, improve tire clearance, and support more aggressive track alignments. Another plus often mentioned is the “tight” feel from the pillowball-style joint, which can help keep alignment more consistent under load compared to worn factory parts.
The trade-offs mostly come down to cost, complexity, and the realities of alignment changes. These arms are typically priced higher than some alternatives, and any meaningful camber change can also influence rear toe—so you should plan on a proper alignment after install and after adjustments. Some owners also point out that access to the rear upper arm adjuster isn’t always the easiest depending on your ride height and exhaust/suspension layout, which can make quick “trackside tweaks” less convenient than other adjustment methods.
Owner feedback tends to cluster around maintenance and expectations. A common theme is: they work well when kept clean and serviced, but like many threaded adjusters, they can become difficult to turn if exposed to grime, road salt, or neglect—so periodic inspection, cleaning, and anti-seize on threads are frequently recommended. Others note that if your primary goal is simply “fix rear camber on a budget,” you may end up considering additional alignment parts (like toe adjustment) anyway. Overall, the Cusco RUCA is best viewed as a quality, performance-oriented tool: excellent when you need the range and are willing to align and maintain it properly.