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SOS MECHANIC CERTIFICATION SUSPENSION & STEERING TEST
2025-2026 QUESTIONS AND CORRECT ANSWERS CURRENTLY
TESTING /ALREADY GRADED A+
Advantages of a large Positive scrub radius-ANSWER-The tire
rolls while turned, resulting in reduced steering effort when
parking.
More room in the engine bay
advantage of Negative Scrub radius-ANSWER-provides center
point steering in the event of a tire deflation, which provides
greater stability and steering control in this emergency
situation.
Advantage of a small positive scrub radius-ANSWER-that the
steering becomes less sensitive to braking inputs, in
particular.
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Disadvantage of a small positive scrub radius-ANSWER-the
contact patch is spun in place when parking, which takes a lot
more effort
Scrub radius is...-ANSWER-the distance in front view between
the king pin axis and the center of the contact patch of the
wheel, where both would theoretically touch the road
The steering axis inclination (SAI) is-ANSWER-the angle
between the centerline of the steering axis and vertical line
from center contact area of the tire (as viewed from the
front).
Loose front wheel bearing adjustment may cause steering
wander while driving straight ahead-ANSWER-True
Negative caster settings may cause steering wander while
driving straight ahead-ANSWER-True
When performing a sector lash adjustment on a recirculating
ball steering gear, the worm shaft is positioned (...)-ANSWER-in
the center of its travel
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A leaking rack piston seal may cause a power rack and pinion
gear to have excessive steering effort in both directions-
ANSWER-True
A leaking inner rack seel may cause a power rack and pinion
gear to have excessive steering effort in both directions-
ANSWER-False
This will increase steering effort in only one direction
A leaking outer rack bulkhead seal may cause a power rack and
pinion gear to have excessive steering effort in both directions-
ANSWER-False
This will increase steering effort in only one direction
A loose rack bearing adjustment may cause a power rack and
pinion gear to have excessive steering effort in both directions-
ANSWER-False
this will reduce steering effort
A faulty power steering gear may cause a PS pump to have less
than specified pressure during a pressure test.-ANSWER-False
A valve in the tester closes the hose between the pump and
the gear
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A sticking pump pressure relief valve may cause a PS pump to
have less than specified pressure during a pressure test.-
ANSWER-True
A bent or damaged rack in the steering gear may cause a power
rack an pinion steering system to have poor steering wheel
returnability.-ANSWER-False
It will cause erratic steering effort
Excessive negative caster may cause a power rack an pinion
steering system to have poor steering wheel returnability.-
ANSWER-True
Worn steering gear mounting bushings may cause bump steer
on a vehicle with power rack and pinion steering-ANSWER-True
worn steering gear mounting bushings may cause unequal tie
rod height, the cause of bump steer
Worn upper strut mounts may cause bump steer on a vehicle
with power rack and pinion steering-ANSWER-False
Worn upper strut mounts don't cause unequal tie rod height
SOS MECHANIC CERTIFICATION SUSPENSION & STEERING TEST
2025-2026 QUESTIONS AND CORRECT ANSWERS CURRENTLY
TESTING /ALREADY GRADED A+
Advantages of a large Positive scrub radius-ANSWER-The tire
rolls while turned, resulting in reduced steering effort when
parking.
More room in the engine bay
advantage of Negative Scrub radius-ANSWER-provides center
point steering in the event of a tire deflation, which provides
greater stability and steering control in this emergency
situation.
Advantage of a small positive scrub radius-ANSWER-that the
steering becomes less sensitive to braking inputs, in
particular.
,2|Page
Disadvantage of a small positive scrub radius-ANSWER-the
contact patch is spun in place when parking, which takes a lot
more effort
Scrub radius is...-ANSWER-the distance in front view between
the king pin axis and the center of the contact patch of the
wheel, where both would theoretically touch the road
The steering axis inclination (SAI) is-ANSWER-the angle
between the centerline of the steering axis and vertical line
from center contact area of the tire (as viewed from the
front).
Loose front wheel bearing adjustment may cause steering
wander while driving straight ahead-ANSWER-True
Negative caster settings may cause steering wander while
driving straight ahead-ANSWER-True
When performing a sector lash adjustment on a recirculating
ball steering gear, the worm shaft is positioned (...)-ANSWER-in
the center of its travel
,3|Page
A leaking rack piston seal may cause a power rack and pinion
gear to have excessive steering effort in both directions-
ANSWER-True
A leaking inner rack seel may cause a power rack and pinion
gear to have excessive steering effort in both directions-
ANSWER-False
This will increase steering effort in only one direction
A leaking outer rack bulkhead seal may cause a power rack and
pinion gear to have excessive steering effort in both directions-
ANSWER-False
This will increase steering effort in only one direction
A loose rack bearing adjustment may cause a power rack and
pinion gear to have excessive steering effort in both directions-
ANSWER-False
this will reduce steering effort
A faulty power steering gear may cause a PS pump to have less
than specified pressure during a pressure test.-ANSWER-False
A valve in the tester closes the hose between the pump and
the gear
, 4|Page
A sticking pump pressure relief valve may cause a PS pump to
have less than specified pressure during a pressure test.-
ANSWER-True
A bent or damaged rack in the steering gear may cause a power
rack an pinion steering system to have poor steering wheel
returnability.-ANSWER-False
It will cause erratic steering effort
Excessive negative caster may cause a power rack an pinion
steering system to have poor steering wheel returnability.-
ANSWER-True
Worn steering gear mounting bushings may cause bump steer
on a vehicle with power rack and pinion steering-ANSWER-True
worn steering gear mounting bushings may cause unequal tie
rod height, the cause of bump steer
Worn upper strut mounts may cause bump steer on a vehicle
with power rack and pinion steering-ANSWER-False
Worn upper strut mounts don't cause unequal tie rod height
