Rear Control Arm

Our sealed Monoball Rear Trailing Arm Bushings (RTAB) are the best solution for completely eliminating deflection and unwanted toe changes on the rear of the E36, E46, and Z4. While rubber and urethane bushings flex during load, the toe can change widely giving you nervous and unpredictable handling. These RTABs have a solid aluminum housing with a high-quality sealed OE bearing. These bushings were developed from years of competition use in various racing and HPDE events. There is simply no better RTAB unless your racing class rules prohibit the use of mono or spherical bearings.

The rear trailing arm bushings take a lot of abuse from acclerating, braking and cornering. The stock rubber bushings are just not up to the task of keeping rear wheel alignment in spec for very long, especially if you have upgraded to stickier tires and a better suspension. The pliable rubber flexes and twists which slows down reaction time and leaves you with a car that feels nervous and 'tail happy'. Urethane helps to control the alignment but issues with fitment, maintenance, and longevity keep us from recommending urethane on anything but a street car. We also offer a Delrin RTAB for cars that must conform to certain racing class rules. These sealed spherical bearings are the best at controlling rear toe alignment.

Our aluminum RTABs are very well made - high grade aluminum alloy and steel CNC'd out of a billet by an ISO 9001 certified manufacturer, each component is either hardcoated or nickel plated. While multiple manufacturers offer two piece designs, our research showed that a one piece bushing is a better design featuring a sealed bearing to keep contaminants out extending the life of the bearing.

Features:

Key Benefits:

• Rear Trailing Arm Monoball eliminates unwanted deflection, maintaining alignment settings and minimizing wheel hop.
• Allows full rear trailing arm articulation for low friction movement and eliminates binding found in rubber and poly bushings.
• Completely streetable: utilizes an OES Lemforder brand sealed, greased ball joint for an extremely long service life with no increase to NVH.

Design Features:

• Housing: Billet CNC 6061-T6 aluminum, type II anodized for exceptional durability and corrosion resistance
• Bearing: OE Mercedes/lemforder 2043520027 Sealed ball joint
• Bearing inserts: CNC machined 303 stainless steel.
• Rebuildable

Clickhere for installation instructions.

This item fits the following BMWs:
1992-1998 E36 BMW 318i 318is 318ic 323is 323ic 325i 325is 325ic 328i 328is 328ic M3
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
2003-2008 Z4 BMW Z4 2.5i Z4 3.0i Z4 3.0si Z4 M Roadster M Coupe

ECS E90 xDrive Lowering Spring Set Transform your E90’s handling and stance with our specially designed ECS Lowering Springs. Built to enhance both cornering capability and ride comfort, these springs provide a balanced drop between 1.0"-1.3", giving your vehicle a sportier profile while keeping a smooth, OEM-like ride. Experience a lower center of gravity for improved stability, enhanced steering feedback, and a sleek look that reduces unsightly wheel gap for a true performance appearance.

Why Choose ECS Lowering Springs?

Better Handling and Stability: By lowering the center of gravity, these springs reduce body roll and improve road grip, delivering precise control through corners. Performance-Driven Design: Linear spring rates tuned for sporty responsiveness without sacrificing comfort, making them ideal for daily driving. Durability You Can Trust: Finished with a flat black powder coating for excellent corrosion resistance, so they look great and last. Specifications

Lowering Range: Front 1.0"-1.2", Rear 1.2"-1.3" Spring Rate: Front 505 lbs/in, Rear 854 lbs/in Ideal for Daily Drivers and Enthusiasts: With rates slightly above factory specs, ECS Lowering Springs provide improved handling without the harshness typical of coilovers, making them perfect for drivers seeking a more refined, performance-focused setup. Take it a step further by adding wheel spacers to achieve the ultimate stance—browse our wide selection of options for the E90 xDrive to complete your suspension overhaul!

ECS Performance Rear Trailing Arm Set Say goodbye to suspension flex and unwanted geometry changes under load with our Performance Rear Trailing Arms, an upgrade engineered to enhance strength and handling precision. Factory steel trailing arms can flex and even fail under harsh conditions, but these trailing arms are built to stand the test of time. Lightweight, rigid, and built from solid 6061-T6 aluminum, these trailing arms offer improved stability and peace of mind, no matter how demanding the road.

Why Upgrade to ECS Rear Trailing Arms?

Engineered for Strength: Constructed from high-grade 6061-T6 aluminum, anodized for corrosion resistance, these arms are designed to last longer and handle tougher conditions than OEM steel arms. Lightweight and Strong: Each arm is 25% lighter than stock, weighing 384 grams versus the factory 517 grams, reducing unsprung weight for better performance. Easy DIY Installation: Designed to fit seamlessly, these trailing arms won’t alter alignment settings, making them a straightforward upgrade for enthusiasts and home mechanics alike. Enhanced Handling: With virtually no flex, they eliminate unwanted suspension changes, providing a smoother, more controlled ride. Kit Includes

Lowering Spring Set: Front and rear springs with precise lowering specs and premium powder coating. Rear Trailing Arms: A set of solid 6061-T6 aluminum trailing arms, ready for direct replacement, along with all necessary hardware. Bolt Torque Spec: 74 ft-lbs