Mustang Rear Lower Control Arm Tech: MM Heavy Duty series control arms

Heavy Duty control arms

• Direct replacement for the stock lower control arm.
• Tubular steel construction is over three times stiffer than the stock control arm.
• Large 2" diameter round steel tube provides maximum stiffness.
• Engineered design prevents binding of suspension movement.
• Unique 3-piece bushing design at the chassis end.
• Center urethane bushing is quite hard to virtually eliminate deflection in the fore/aft direction.
• Softer outer bushings allow the angularity required for proper articulation of the rear suspension.
• Large Teflon-lined spherical bearing at the axle end allows freedom of motion for both pivoting and angularity, preventing unwanted deflection while still allowing the angularity required for proper articulation.
• Design combination of 3-piece urethane bushings and spherical bearings prevents damage to the torque-boxes.
• Greatly reduces axle wind-up.
• Minimal change in NVH because the urethane is located at the chassis end.
• Swaybar mounting brackets are 3/16" thick steel, shaped to increase their strength, and are welded on both sides.
• Powdercoated black.
• Includes long-lasting grease to lubricate the urethane bushings.
• Grease fitting to ease future lubrication.
• Spring perch location on non-adjustable arms does not change ride height.
• Available with adjustable height spring perch.

The MM Heavy Duty series Rear Lower Control Arms are a standard upgrade to improve the performance of a street-driven Mustang. These arms utilize specially designed 3-piece urethane bushings at the chassis end. These bushings have a hard center section to prevent fore and aft deflection, and softer outer sections to allow the angular motion necessary to prevent bind and torque box damage.

At the axle end, we use a high quality Teflon-lined spherical bearing to precisely locate the rear axle. Unlike more commonly used bushing materials such as hard urethane, Delrin, or steel, spherical bearings allow freedom of motion for both pivoting and angularity, which is what allows for proper articulation of the rear suspension. The unique combination of 3-piece urethane bushings and spherical bearings is ideal for street-driven cars, because it will not appreciably increase noise transmission.

Unlike other brands, we place the 3-piece urethane bushing at the chassis end of the control arm. If a spherical bearing is placed at the chassis end of the control arm and a urethane bushing at the axle end, the control arm will tend to stay in alignment with the axle. This will cause the spring to arc with body roll, and change the effective wheel rate. The bushing orientation of the MM arms also allows less NVH (noise, vibration, and harshness) transmission into the chassis.

To adjust, or not to adjust...
Heavy Duty control arms are available in two styles: Ride height adjustable or non-adjustable.

Adjustable Heavy Duty control arms

• Allows easy changes to ride height, both up and down.
• Raise the rear ride height by up to 2 inches
• Lower the rear ride height by as much as 1 inch.
• Adjust ride height without the need to jack the car off the ground.
• Improve traction by fine-tuning the instant center location and anti-squat geometry by changing the ride height.
• Aids with adjusting the corner-weights.
• Available in both series: Heavy-Duty and Extreme-Duty.

Standing Starts and RLCA Bushings
Urethane rear lower control arm bushings should not be used for any type of drag racing. If hard launches are part of your lifestyle, then you want the MM Extreme Duty Rear Lower Control Arms.

Specific tech about the MM Extreme Duty control arms

Specific tech about the MM Road Race control arms

General Tech about MM rear lower control arms

Mustang Rear Lower Control Arm FAQs