SPL Parts 2014+ BMW M2/M3/M4 (F8X) Rear Upper Control Arms

SPL RUA F8X Rear Upper Control Arms for 2014-2021 BMW M2 / M3 / M4

The SPL RUA F8X Rear Upper Control Arms are an essential alignment upgrade for any lowered or performance-oriented BMW F80 M3, F82/F83 M4, or F87 M2. The factory BMW rear wishbone and guide link use rubber bushings that allow camber and toe to shift under load, contributing to unpredictable rear handling and accelerated inner-edge tire wear. The SPL RUA F8X replaces both the rear wishbone and rear guide links with a complete 4-arm kit featuring gun-drilled 2024 aluminum links and 360-degree rotating 6061-T6 aluminum clamps. Adjusting camber requires only a 3/16 inch allen key to loosen the clamp screws, rotate the link to the desired length, and retighten. FK Spherical Bearings with Teflon liners eliminate bushing deflection for precise, consistent rear camber alignment whether chasing street comfort or circuit performance.

Features and Benefits

• Complete kit replaces both rear wishbone and rear guide links for total upper-arm rear camber control
• Gun-drilled 2024 aluminum links reduce unsprung weight without sacrificing stiffness
• 360-degree 6061-T6 rotating clamp design allows tool-free camber adjustment with a single 3/16 in. allen key
• Blue anodized titanium socket-head cap screws further reduce weight and resist corrosion
• Tapered stainless steel knuckle mount spacers for proper geometry at the hub
• 3-piece Teflon-lined FK Rod Ends with PTFE liner: self-lubricating, self-cleaning, rated from -65 to 325 degrees F
• Eliminates bushing deflection that causes camber and toe variation under hard cornering and acceleration
• Wide adjustment range for precise street or track alignment on lowered BMWs
• Sold as a complete 4-arm kit for one vehicle, made in the USA

Fitment

Specifications

What Is Included

• 4 x SPL RUA F8X Rear Upper Control Arm links (2 wishbone, 2 guide links)
• 6061-T6 aluminum 360-degree rotating clamps
• Blue anodized titanium socket-head cap screws
• Tapered stainless steel knuckle mount spacers
• 3-piece Teflon-lined FK Rod Ends pre-installed
• Installation instructions

Frequently Asked Questions

What does the SPL RUA F8X replace on the BMW M3 and M4?
The SPL RUA F8X replaces the factory rear wishbone and rear guide links (upper control arms) on the F80 M3, F82/F83 M4, and F87 M2. The kit includes four total arms for complete upper rear camber adjustment on one vehicle.

How much rear camber adjustment does the SPL RUA F8X provide?
The SPL RUA F8X provides a wide rear camber adjustment range well beyond the factory eccentric bolt range, which is frequently insufficient on lowered F80/F82/F83/F87 BMWs. Exact degree range varies by vehicle height and configuration.

Is the SPL RUA F8X suitable for daily driving?
Yes. The Teflon-lined FK Rod Ends operate quietly and smoothly from -65 to 325 degrees F. The SPL RUA F8X is engineered for combined street and track use and is a popular choice for lowered M3 and M4 owners who need to correct inside-edge tire wear.

Does installing the SPL RUA F8X void my BMW warranty?
Under the Magnuson-Moss Warranty Act, BMW cannot void unrelated warranty coverage due to the installation of an aftermarket suspension part. The dealer must demonstrate that the SPL RUA F8X directly caused the claimed failure.

Does the SPL RUA F8X fit the G80 M3 and G82 M4?
The SPL RUA F8X is designed for the F8X generation (F80 M3, F82/F83 M4, F87 M2, 2014-2021). For the G80 M3 and G82/G83 M4, see the SPL RUA G8X. The fitment for the G-generation differs from the F-generation.

How is camber adjusted with the SPL RUA F8X?
Loosen the blue titanium clamp screws on the rotating clamp with a 3/16 inch allen key. Rotate the aluminum dogbone to thread the rod ends in or out, changing link length and therefore rear camber. Re-tighten the clamp screws to 150 in-lb maximum to lock the setting.

What tools are required for installation?
Basic hand tools including ratchet, sockets (6mm, 8mm, 16mm, 18mm, 21mm), a T40 Torx socket, and a calibrated torque wrench. An alignment shop visit is required after installation.

Can I use the SPL RUA F8X on a track-only M4?
Yes. The SPL RUA F8X is widely used in club racing and HPDE applications where consistent, lockable rear camber settings are required between sessions. The 360-degree clamp design allows fast trackside adjustments with minimal tooling.

Installation Overview

1. Raise and support the rear of the vehicle; remove rear wheels.
2. Remove undertray panels using 8mm and 16mm sockets as needed for access.
3. Remove the OEM rear wishbone and guide link bolts at the subframe and knuckle ends.
4. Pre-set the SPL RUA F8X links to match OEM arm lengths before installing.
5. Install the subframe end first, then connect the knuckle end of each arm.
6. Torque subframe end bolts to 100 Nm (75 ft-lb); torque knuckle-side nuts to 180 ft-lb using a calibrated torque wrench.
7. Lock the rotating clamp screws to 150 in-lb maximum with the 3/16 in. allen key.
8. Sweep suspension through full travel to confirm no binding.
9. Reinstall wheels and lower the vehicle to ride height.
10. Perform a professional four-wheel alignment to set rear camber and toe.
11. Re-check all fastener torques after the first 100 miles and first track session.

California Prop 65 Warning: This product can expose you to chemicals including lead and chromium, which are known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.