Suspension Kits Research Guide

Suspension Kits Research Guide Glossary Terms

• Apex
• Body Roll
• C-section
• Camber
• Center of Gravity
• Differential
• Helix
• Jounce
• Laissez-Faire
• Magnuson-Moss Warranty Act
• Pitman Arm
• Polyurethane
• Powertrain
• Slip Yoke Eliminator
• Speed Sensor
• Spindles
• Steering Knuckle
• Suspension Travel
• Tenth Amendment
• Wheel Shimmy

Suspension Kits Research Guide Glossary Definitions

Apex

In racing parlance, an apex is the straightest line through a curve and the path that allows the maximum speed with minimal braking. Generally, this line runs extremely close to the edge of the track, and it is not unusual for tires to clip the racetrack's rim.

Body Roll

As an automobile steers through a curve, gravity shifts the vehicle's weight to the outside of the curve. You can feel this force pulling you in the opposite direction of a curve or turn. Unfortunately, body roll hinders your handling because the concentration of weight on one side of the vehicle lessens traction and impairs steering. Effective antidotes to the scourge of body roll are lowering your vehicle's center of gravity, installing stiffer springs and mounting an anti-sway bar.

C-section

While most people associate the term C-section with an invasive birthing procedure that's named after a famous Roman General and epileptic, it has more than one meaning. A C-section also refers to the process of cutting out a notch from a vehicle's frame to allow proper clearance during a serious suspension lowering.

Camber

From the Latin word "camur" meaning "curved" or "bent," camber refers to the angle of your wheel. If a wheel is perfectly straight so that the top of the tire is parallel with the bottom, then it has a 0 degree camber. Negative camber is when the top of the tire bends inward, towards the vehicle. Likewise, positive camber is when the tire bends outward, away from the vehicle.

Center of Gravity

Without going into an extensive physics lecture, the center of gravity is basically a point on an object where its weight is balanced and in harmony. Adjusting an automobile's center of gravity by lifting or lowering its suspension has profound effects on handling, steering and cornering.

Differential

Sometimes called the "pumpkin," a differential is the round hump in the middle of an axle. More than just decorative, the differential houses a set of gears that transmits torque energy out to your tires and allows them to spin at different speeds during turns.

Helix

Anyone who has ever seen a corkscrew or a spring has seen a helix-it's simply a spiral. Basic as it may seem, life as we know it would be radically different (if existent at all) if not for the helix. That's because DNA and many proteins form helical shapes, which in turn dictate how we and the world are shaped.

Jounce

Closely related to words like "jolt" and "bounce," jounce refers to the up-down motion of a wheel that hits a bump.

Laissez-Faire

The economic system championed by Adam Smith and perfected by Enron, laissez-faire refers to free market economics in which government regulation is slim or non-existent. This hands-off system reached its heyday during the industrial revolution, fell out of favor during the Great Depression, and was later revived by such world leaders as President Ronald Reagan and General Augusto Pinochet.

Magnuson-Moss Warranty Act

(US Code - Title 15, Chapter 50, Sections 2301-2312)
Legally, a vehicle manufacturer cannot void the warranty on a vehicle due to an aftermarket part unless they can prove that the aftermarket part caused or contributed to the failure in the vehicle. If your vehicle manufacturer fails to honor emission/warranty claims, contact EPA at (202) 260-2080 or www.epa.gov. If federal warranty protection is denied, contact the FTC at (202) 326-3128 or www.ftc.gov.

Pitman Arm

One of the most essential components in your steering system, the pitman arm connects the steering box with the drag link. In other words, the pitman arm transfers the motion of your steering wheel down to the linkage that navigates your wheels. Often, a lift kit changes the distance between the steering box and the drag link, so a longer pitman arm is needed.

Polyurethane

From skateboard wheels to floor sealants, polyurethane is the golden child of the polymer family. This chemistry lab concoction is also widely used in place of rubber for suspension bushings and dust boots on shocks.

Powertrain

Not to be confused with Soul Train or Gravy Train, a powertrain refers to all the parts on a vehicle that produce and transmit energy. In most cases, that would be the engine, transmission and differential.

Slip Yoke Eliminator

Don't let its name scare you-a slip yoke eliminator is a simple part. As a vehicle lifts upwards, the angle of the driveshaft becomes ever steeper. This extreme slope sends vibrations shimmying through the vehicle, and it can even lead to a snapped driveshaft. A slip yoke eliminator attaches to the end of a drive shaft, correcting the angle and lengthening the shaft for vibration-free driving.

Speed Sensor

The driving force behind your speedometer and odometer, a speed sensor is a device (usually mechanical) that transmits the rate of wheel rotation to your instrument cluster. Speed sensors are calibrated to a vehicle's stock wheels, tires and gear ratios, so altering any of these components will result in faulty speed readings and inaccurate odometer tally.

Spindles

Basically, a spindle is a small shaft that the bearing and wheel hub mount onto. Lift kits and lowering kits often use new spindles to augment a vehicle's height.

Steering Knuckle

Steering knuckles are the pivot points that turn yours wheels and let you steer. Many lift kits use taller steering knuckles to send pickups and SUVs soaring upwards.

Suspension Travel

Suspension components fall into 2 camps: fixed and moving. A fixed component, such as a spindle, remains rigid and does not move. On the other hand, moving parts, like shocks and springs, are hardly ever stationary. Suspension travel is the maximum distance that the moveable parts can travel away from the fixed parts. By their very nature, lift kits lengthen suspension travel while lowering kits reduce suspension travel.

Tenth Amendment

The final amendment in the original Bill of Rights, the Tenth Amendment declares, "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people." In other words, individual states have the power and discretion to make and enforce their own laws, so long as those laws do not conflict with other constitutional provisions.

Wheel Shimmy

Wheel shimmy refers to the obnoxious side-to-side wobble of a vehicle's front tires. While shimmy is generally caused by a misalignment or faulty steering linkage, it can also occur because of the dramatic alteration of a suspension's geometry after installing a lift kit, a heavy winch or oversized wheels and tires. Steering stabilizers greatly reduce wheel shimmy on lifted rigs.