Traction is a word that repeatedly pops up in any discussion about upgrading suspension systems. Traction is very important whether you’re tackling some twisty mountain roads or trying to win a drag race. There are control arms designed more towards drag racing, but few Mustang owners limit themselves to one type of performance event. That’s where installing high strength, lightweight aftermarket control arms can benefit your Mustang in any driving situation—street, strip or road course.
Rear control arms are also known as trailing arms. Their function is to locate and control the rear axle. Factory arms are designed to provide a comfortable ride and reasonably good handling. Compromises are the order of the day with factory suspension components, because as much as people appreciate a fine handling car, they complain if the ride is too stiff.
Performance Mustang owners actually appreciate a firmer ride and the improved control. Enthusiasts don’t like an overly soft and sloppy ride.
Besides more rigid control arms, aftermarket arms usually come with performance bushings. Urethane bushings minimize deflection. There is a balance between having bushings that are too hard and ones that still allow the suspension to move. Special three-piece bushing systems provide suspension control without binding. Varying bushing hardness helps fine tune a suspension system.
A huge benefit of aftermarket control arms is their significantly lighter weight. Typically, chrome moly and billet aluminum arms can weigh 30-50 percent less than original equipment arm weighs. That weight savings is very beneficial because it’s unsprung weight. Reducing unsprung weight allows the suspension to react faster. Adding aftermarket rear control arms is an easy way to improve control and increase traction.
1351 NW Steeda Way
Pompano Beach, FL 33069
Mustang rear lower control arms come in a variety of styles. Shown here is the Ford factory unit (bottom), a Steeda tubular chrome moly arm (middle) and a Steeda street and race billet lower trailing arm. The best aftermarket arms weigh about half the stock ones.
Installing new rear control arms is pretty much a remove and replace operation. The stock arm shown here has the emergency brake cable passing through it, so the e-brake must be disconnected.
High performance trailing arms such as these Steeda billet lower arms for 2005-06 Mustangs add strength while reducing unsprung weight. The arms can be had with either urethane bushings or rod ends. Urethane bushings are shown here.
Rear upper control arms are available in a variety of styles at varying price points. Shown here is a Steeda heavy duty boxed upper arm (below) and a Steeda aluminum arm (top). The boxed arm costs less than half of what the aluminum unit costs. These control arms fit ’79-’04 Mustangs.
It’s not difficult to install billet lower control arms, but the car must be safely supported on jack stands. Having access to a hoist greatly simplifies the job.
You can fine tune rear suspension control and adjust driveshaft-to-differential pinion angle by installing adjustable upper control arms. This example is for 2005-06 Mustangs, but similar items are available for ’79-’04 Mustangs.
Lower control arms with rod ends instead of bushings are too harsh for the street and should only be used on off road racing suspension systems. These arms eliminate wheel hop.