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

The rear lower control arms on E82/E9X models are the weakest link in the rear suspension. The arm is made from folded sheetmetal and it bends and deforms easily. Not only will it deform from potholes and curbs, tow truck drivers love to hook onto them without realizing how weak they are. We have seen other race teams complete the box section to make them stronger. A bent arm will throw off the geometry in the suspension, potentially affecting handling and tire wear. These aluminum arms are both lighter and stronger than the factory sheetmetal arms and is the best solution for chronic bending of the stock arm. These are a direct replacement to your stock arms with no changes needed to your alignment. New high-grade hardware is included.

Note: the stock arm is designed from the factory to be intentionally weak. These arms will bend so that something else in the suspension does not break. Our race cars used the stock sheetmetal arm but we replaced them often. We found that it was better to finish a race with a bent arm than not finish due to a catastrophic failure. The ECS arms are still designed to be the weakest link but are far stronger than the factory arm and will not bend as easily.

This item fits the following BMWs:

2008-2013 E82 E88 BMW 128i 135i 1M Coupe
2006-2011 E90 BMW 325i 325xi 328i 328xi 330i 330xi 335i 335xi M3 - Sedan
2007-2011 E91 BMW 325i 325xi 328i 328xi - Touring Wagon
2007-2013 E92 BMW 328i 328xi 335i 335is 335xi M3 - Coupe
2007-2013 E93 BMW 328i 335i 335is M3 - Convertible