Chapter 112 - Suspension System Principles and Components Flashcards

Ladder Frame

Perimeter Frame
Stub-type Frame or Cradle

Unibody Frame
The area separating the engine compartment from the passenger compartment
Bulkhead
Weight of the components that move up and down (springs, wheels, suspension links, struts, etc.)
Unsprung Weight
Weight of vehicle that does not move up and down (engine, cabin, seats, frame, etc.)
Sprung Weight
Suspension that allows movement of one wheel without affecting the opposite wheel, as in solid axles
Independent Suspension
Part of the suspension that buffers between the suspension and frame to absorb vertical movement and transfers part of the vehicle weight to the suspension component (ex. lower control arm) it rests on
Spring
Name 4 types of springs
Leaf Spring
Torsion Bar
Coil Spring
Air Spring
The amount of force in pounds it takes to compress a spring 1 inch
Spring Rate (K)
The 4 characteristics that affect strength of a coil spring
Coil Diameter
Number of Coils
Height of Spring
Diamater of Steel that Forms the Spring
Name two examples to vary spring rate
Frequency of Coils in Spring (less to more dense)
Decreasing Coil Diamater (tapered)
What is spring frequency and how is it affected?
The speed that a spring oscillates/bounces. Stiffer springs have a higher spring frequency than softer springs.
The ratio of wheel travel to spring travel. For example, the coil spring mounted on a lower control arm compresses 1 inch per 2 inches that the wheel travels vertically.
Wheel Rate
The specific area where a coil spring is mounted, usually lined with a hard rubber or plastic cushion called insulators
Spring Seat
A scratch, nick, or pit caused by corrosion on a spring’s epoxy coating that can lead to spring failure
Stress Riser
Springs constructed of one or more strips of long, narrow spring steel
Leaf Springs
Part that holds the leaves of a leaf spring together
Center Bolt or Centering Pin
How and to what are both ends of a leaf spring attached?
One is connected directly to the immovable frame, and the other is connected to a movable hanger called a shackle
Why are shackles necessary?
It allows movement of the leaf spring, as it extends/straightens whena bump is hit
A spring that is long, round, hardened-steel straight bar
Torsion Bar
Describe how a torsion bar is mounted
One end is attached to a non-twisting adjustable anchor arm on the frame, and the other is attached to a control arm (generally LCA) that allows twisting
Why are two suspension links (i.e. upper AND lower control arms) needed?
It prevents transverse (side-to-side/in-and-out) and longitudinal (forward-backward) movement of the wheels