Flashcards in A - Frame and Suspension Fundamentals Deck (30):
List three functions of a vehicle frame.
Provide a platform on which the major vehicle components are attached, support the load that the vehicle intended to carry, and resist shock and torsional loads when the vehicle is in operation.
The point at which the maximum force is concentrated on a frame is called the:
Maximum bending moment.
A ladder type frame is made up of:
Parallel frame rails and cross members.
The function of frame cross members is to:
Provide strength and rigidity to the frame assembly.
Which one of the following is not a common frame rail shape: Trapezoid, channel, box, or I-beam.
The surface between the flanges of an I-beam frame rail is called the:
What is the function of a gusset that is attached to a frame cross member?
Gussets provide resistance to frame weaving.
True or False: The size and shape of frame components affects the strength of the frame.
Define the term Yield Strength as it applies to the strength of frame materials.
Yield strength refers to the amount of stress that the material can withstand before becoming permanently deformed.
Which of the following frame materials would have the highest yield strength: Mild steel, High strength, low alloy steel, heat-treated alloy steel, or copper-aluminum alloy.
Heat-treated alloy steel.
The term Section Modulus refers to the strength of frame components based on:
Height, width, thickness, and shape.
True or False: A frame with a high resisting bending moment (RBM) has less strength than a frame with a low RBM.
False, The greater the RBM, the greater the strength of the frame.
List four functions of a vehicle suspension system.
Secure the axles to the frame while maintaining proper alignment, Support the weight of the vehicle and its cargo while maintaining lateral stability, Cushion shock loads, and Allow axle movement so that the tires follow the contour of the road.
True or False: The term Unsprung Weight refers to the weight of the vehicle and its load.
False, The combined weight of the components below the connection point is called unsprung weight because it is located below the suspension system.
The suspension system must hold the axles in alignment with the frame. This means that the:
Wheels are held parallel to the frame rails.
Three of the most common types of energy-absorbing devices used in suspension systems are:
Leaf spring, rubber cushion, rubber air spring.
True or False: The energy-absorbing device of a suspension system is released when it rebounds.
Solid-mount suspension systems are best suited to applications that:
Operate on rugged terrain.
Equalizer beams reduce the effect of shock loads to the frame by:
Axles are stabilized against braking and acceleration forces by:
Longitudinal torque rods.
The function of transverse torque rods is to:
Provide improved side-to-side stability by distributing side loads more evenly across the entire length of the axle.
True or False: Progressive leaf springs provide a load spring rate when the vehicle is unloaded and a high spring rate under load.
Auxiliary springs help to support the vehicle when it is:
True or False: Spring shackles accommodate changes in spring length as the suspension jounces and rebounds.
The main function of a shock absorber is to:
Dampen spring oscillation.
The function of vertical drive pins on a rubber cushion type suspension is to:
Allow the saddles to move up and down as the load cushions deflect, thus maintaining alignment of the saddles with the frame rails.
An advantage that air spring suspensions have over other suspension types is that they provide superior:
State the function of the pressure protection valve in an air spring suspension.
Ensures that a minimum safe pressure is maintained in the air reservoir for air brake operation if a leak occurs in the suspension air system.
The ride height control valve supplies air to the air springs when:
Additional load is added to the vehicle.