FAQs & Tech Tips

MM News

New! MM Technical Services: MM’s Engineering Team will provide setup recommendations specifically tailored for your Mustang. Get help choosing options for a Maximum Grip Box, deciding on coil-over spring rates, selecting a brake master cylinder, and advice on converting your Fox to Hydroboost.

New! Swapping a Coyote into a Fox Mustang? MM's Hydroboost Conversion Kits allow easy installation of a 1996-2004 Mustang Hydroboost power brake assist unit into a 1979-1993 Mustang.

New! Swapping an IRS into your Fox Mustang? MM makes it easier with a brake line kit made just for this conversion. Bolts-in, with no cutting or flaring of brake lines. Designed to fit standard IRS brake hoses.

New! MM now offers a tool for the giant nut securing a Mustang Hydroboost. This MM socket fits the 1-7/8" nut holding the Hydroboost to the firewall mount. Required when changing a Hydroboost unit.

New! MM's billet aluminum Pedal Box Spacer for Fox Mustangs. Replace the breakage-prone OEM plastic spacer when converting to manual brakes or Hydroboost.

Canadians! Please read the latest about ordering from Canada/shipping to Canada.

/DRIVE
We've posted the parts list and link to the video of MM's Mustang in /DRIVE Tuner car Shootout

2005+ Mustang Rear Lower Control Arm FAQs

Why change from the stock Mustang rear lower control arms?
Because the stock lower control arms were designed for a grocery-getter, not a performance car. One of Ford's main goals when they designed the rear suspension was to avoid complaints about NVH (Noise, Vibration, Harshness) from little old ladies. As performance enthusiasts, we have very different goals.

What do the rear lower control arms do?
Rear lower control arms, along with the upper arm, control axle rotation.

All of the forces that accelerate the car pass through the rear lower control arms: The tires rotate on the pavement, moving the axle forward. The axle pushes on the rear lower control arms, moving the rest of the car forward. The control arms, and their bushings, must withstand those forces.

What's wrong with the stock control arms?
In stock form, the rubber bushings in the control arms allow excessive deflection that prevents the rear axle from maintaining its correct position under the chassis. The axle is allowed to shift forwards, backwards, and skew at an angle under the car. This is the primary cause of wheel hop, and leads to poor traction and poor handling.

The stock arms are made of stamped steel. That style of construction is very cheap for mass production, but it does not make for a rigid control arm. Deflection of the steel arm contributes to wheel hop.

More Tech

General Tech about MM 2005+ rear lower control arms

Specific tech about the MM 2005+ Street Performance control arm series

Specific tech about the MM 2005+ Extreme Duty control arm series

Specific tech about the MM 2005+ Road Race control arm series