Potential test questions: Topics to know
1.
Steering Linkage identification
2
TOOT (Toe out on Turns)– use 20° as a
reference point if measuring
3
A.K.A – Ackerman Principle or Turning Radius (Angle)
4
Unloading Ball Joints – unload loaded supporting ball
joint and have air gap at rubber jounce pad
5
Coil springs and stabilizer bars
6
Axial and radial movement
7
Suspension – looseness tends to allow suspension to
go toward the negative camber
8
Ride height importance
9
Purging a shock, getting the air out
10
Low tire pressure pull
Shake Down procedures.
Should usually be done at normal curb height position. This means that components such as control
arms are in the normal position of driving down the road. This is where the most wear can occur. If the
technician lifts the vehicle with the control arms hanging down, this does two
things. It presses the control arm
against the rubber rebound stop and also places the control arm in a position
where is might not be worn.
UNLOADING
BALL JOINT
Allows tire to pivot, swivel, support vehicle; unloading
means to get rid of spring tension
1.
Purpose:
·
Support car
·
Allow to pivot, swivel
·
SLA Type 1 is easiest to unload
·
What type of spring tension?
·
Load carrying ball joint
·
Non-Load carrying (follower) ball joint
·
Load carrying ball joint has spring supporting the
control arm, Type 1 has spring on lower control arm (lower ball joint is load
carrying) and Type II has spring on upper control arm.
·
Follow path from the frame through spring to ground –
which ever ball joint this path passes through is the load supporting ball
joint
·
Unload loaded ball joint – SLA 1, support with stands
as close to the ball joints as possible; use pry bar at tire to lift.
Will pull apart if it has looseness.
·
Must have air gap at rubber striker pad (bumper)
·
2 things to do before checking Ball Joints:
·
Unload the load supporting ball joint
·
Must have air gap at rubber striker pad (this will insure that the ball joint is
unloaded)
·
SLA Type 1 is easiest to check ball joint
wear.
SLA Type 2 (with spring on upper
control arm)
1.
Lift
2.
Install wedge (special tool)
3.
Jack stand
·
Ball joints can be held in place by:
1.
Pressed fit
2.
Riveted
3.
Screw in type or threaded
4.
Bolted
Wear Indicator Ball Joint – usually on rear wheel drive
·
Look at boss that grease fitting screws into
·
Boss should stick out .050” when new
·
As the ball joint wears, the boss will move up.
It should be replaced when the boss
is either
flush with housing or has moved up
into ball joint.
·
Must be checked loaded