Heavy Duty Truck Systems – Chapter 26 – Lecture Summary & Practice Questions
What is used to load the leaves in a spring pack under tension to provide its self-dampening
properties? - ANS ✔✔center bolt
In an air suspension, what happens to the air in the air bags when a height control valve lever is
raised upward off horizontal? - ANS ✔✔bag is further inflated
A spring pack has a single cracked leaf. Technician A says that the spring pack should be replaced
as a unit. Technician B says that the fractured leaf can be repair welded provid-ing it is not the
main leaf. Who is correct? - ANS ✔✔A only
Axle alignment on a tandem rear leaf spring suspension is adjusted by: - ANS ✔✔rotating the
eccentric adjustment bolts
A truck recently had both front spring packs replaced. The driver complains that it is dif-ficult to
steer the truck straight ahead. Technician A says that this could be caused by in-stalling the
caster shims backward. Technician B says that this condition could be caused by seized spring
pins. Who is correct? - ANS ✔✔A only
Which of the following would be the most likely road handling result when a spring pack
centerbolt breaks on a front suspension? - ANS ✔✔bouncing front end
What is the function of torque arms on a suspension system? - ANS ✔✔all the above
The most compressed condition of a spring is known as: - ANS ✔✔jounce
A leaf-type spring suspension that has a variable deflection rate obtained by varying the
effective length of the spring assembly is known as: - ANS ✔✔progressive spring suspension
What is used to load the leaves in a spring pack under tension to provide its self-dampening
properties? - ANS ✔✔center bolt
In an air suspension, what happens to the air in the air bags when a height control valve lever is
raised upward off horizontal? - ANS ✔✔bag is further inflated
A spring pack has a single cracked leaf. Technician A says that the spring pack should be replaced
as a unit. Technician B says that the fractured leaf can be repair welded provid-ing it is not the
main leaf. Who is correct? - ANS ✔✔A only
Axle alignment on a tandem rear leaf spring suspension is adjusted by: - ANS ✔✔rotating the
eccentric adjustment bolts
A truck recently had both front spring packs replaced. The driver complains that it is dif-ficult to
steer the truck straight ahead. Technician A says that this could be caused by in-stalling the
caster shims backward. Technician B says that this condition could be caused by seized spring
pins. Who is correct? - ANS ✔✔A only
Which of the following would be the most likely road handling result when a spring pack
centerbolt breaks on a front suspension? - ANS ✔✔bouncing front end
What is the function of torque arms on a suspension system? - ANS ✔✔all the above
The most compressed condition of a spring is known as: - ANS ✔✔jounce
A leaf-type spring suspension that has a variable deflection rate obtained by varying the
effective length of the spring assembly is known as: - ANS ✔✔progressive spring suspension
