Control Arm Adjustment
– Control Arm Movement Concepts
– Inboard shim adjustment
– Outboard shim adjustment
– Slotted frame / Eccentric cam
– Symmetrical lower arm adjustment
– Asymmetrical Upper and Lower
control arm adjustment
Courtesy of Hunter Engineering Company
Positive Camber Change
(Symmetrical Upper Control Arm)
 Move
front and rear of
upper control arm
outward equal amounts
Front
1/16” equals 1/4°
1/8” equals 1/2°
1/4” equals 1 degree
Courtesy of Hunter Engineering Company
Negative Camber Change
(Symmetrical Upper Control Arm)
 Move
front and rear
of upper control arm
inward equal
amounts
Front
1/16” equals 1/4°
1/8” equals 1/2°
1/4” equals 1 degree
Courtesy of Hunter Engineering Company
Positive Caster Change
(Symmetrical Upper Control Arm)
 Move
the front of
the control arm
outward and the
rear of the control
arm inward equal
amounts
Front
1/32” equals 1/2 degree
1/16” equals 1 degree
1/8” equals 2°
Courtesy of Hunter Engineering Company
Negative Caster Change
(Symmetrical Upper Control Arm)
 Move
the front of
the control arm
inward and the rear
of the control arm
outward equal
amounts
Front
1/32” equals 1/2°
1/16” equals 1°
1/8” equals 2°
Courtesy of Hunter Engineering Company
Positive Camber & Caster
(Symmetrical Upper Control Arm)
Front
 Move
the front of
the control arm
outward
1/16” equals 1/2°
caster & 1/4° camber
1/8” equals 1° caster
& 1/2° camber
Courtesy of Hunter Engineering Company
Negative Camber & Caster
(Symmetrical Upper Control Arm)
 Move
the front of
the control arm
inward
Front
1/16” equals 1/2°
caster & 1/4° camber
1/8” equals 1° caster
& 1/2° camber
Courtesy of Hunter Engineering Company
Positive Camber & Negative
Caster (Symmetrical Upper Control Arm)
 Move
the rear of the
control arm outward
Front
1/16” equals 1/2°
caster & 1/4° camber
1/8” equals 1° caster
& 1/2° camber
Courtesy of Hunter Engineering Company
Negative Camber & Positive
Caster (Symmetrical Upper Control Arm)
 Move
the rear of the
control arm inward
Front
1/16” equals 1/2°
caster & 1/4° camber
1/8” equals 1° caster
& 1/2° camber
Menu
Courtesy of Hunter Engineering Company
Inboard Shims
Front
Menu
Courtesy of Hunter Engineering Company
Camber Increase
 Remove
equal
thickness shim
from front and
rear
Front
1/16” = 1/4°
1/8” = 1/2°
1/4” = 1°
Courtesy of Hunter Engineering Company
Remove
Remove
Shims
Camber Decrease
 Add
equal
thickness shim
from front and
rear
1/16” = 1/4°
1/8” = 1/2°
1/4” = 1°
Front
Add
Add
Shims
Courtesy of Hunter Engineering Company
Caster Increase
 Remove
shim
from front and
add to rear
Front
1/32” = 1/2°
1/16” = 1°
1/8” = 2°
Courtesy of Hunter Engineering Company
Move
Shims
Decrease Caster
 Remove
shim
from rear and
add to front
Front
1/32” = 1/2°
1/16” = 1°
1/8” = 2°
Menu
Courtesy of Hunter Engineering Company
Move
Shims
Outboard Shim (symmetrical)
 Reverse
the shim
movement shown
for Inboard Shims
 All other factors stay
the same
1/16” equals 1/4° camber
1/16” equals 1/2° caster
Menu
Courtesy of Hunter Engineering Company
Slotted Frame Adjustment
 Upper
Control
Arm
 Changes Camber
and/or Caster
 Methods:
– Hit and Miss
– Slotted Formula
Menu
Courtesy of Hunter Engineering Company
Eccentric Cam Adjustment
 Upper
Control
Arm
 Changes Camber
and/or Caster
 Methods:
– Same as slotted
control arm
– More controllable
Menu
Courtesy of Hunter Engineering Company
Ford / Lincoln/ Mercury
 Eccentric
Adjusters for
front camber
and caster.
 Loosen lock nut
and rotate large
lower nut to
adjust angles.
Menu
Courtesy of Hunter Engineering Company
Slotted Control Arm Formula
 Reduce
specification tolerances to:
.25° (1/4) camber tolerance
.50° (1/2) caster tolerance
 Lock
the service brakes
 Level and lock the front sensors
 View the front bar graph screen for
front camber and caster
Courtesy of Hunter Engineering Company
Camber and Caster Adjustment
 Is
the null indicator
equal distance from
center on both bar
graphs?
NO Requires two moves
YES Requires one move
Courtesy of Hunter Engineering Company
Null indicators are not equal
 Which
end of the control arm must move
to make both null indicators move
toward the center of their respective
graphs?
– Camber (+) & Caster (+) - front moves out
– Camber (-) & Caster (-) - front moves in
– Camber (-) / Caster (+) - rear moves in
– Camber (+) / Caster (-) - rear moves out
Courtesy of Hunter Engineering Company
Null indicators are not equal
 Move
the control arm until both null
indicators are equal distance from the
center of their respective graphs.
Courtesy of Hunter Engineering Company
Null indicators are equal
 Move
the end of the control arm which
will make both null indicators move
toward the center of their respective
graphs.
Courtesy of Hunter Engineering Company
Symmetrical Lower Control
Arm
 Reverse
the
upper control arm
movements
 All other factors
stay the same
1/16” equals 1/4°
camber
1/16” equals 1/2°
caster
Menu
Courtesy of Hunter Engineering Company
Asymmetrical Control Arm
Adjustment
 The
adjuster furthest
from the ball joint
will:
have the greatest
effect on caster
have the least effect
on camber
Menu
Courtesy of Hunter Engineering Company
Asymmetric Upper Control
Arms
 Add
or remove
shims equally to
change camber
 Add or remove
shims from the
pack furthest from
the ball joint to
adjust caster
GM G20 Van
Courtesy of Hunter Engineering Company
Asymmetrical Lower Control
Arm
 Rotate
the
eccentric closest
to the ball joint to
adjust camber
 Rotate the
eccentric furthest
from the ball joint
to adjust caster
Menu
Courtesy of Hunter Engineering Company
Common Adjustments
Front Suspension
Lower control arm
Lower strut
Upper Strut plate
Ball joint
Strut rod
Bushing or threaded insert
Rear Adjustments
Common Rear Adjustments
Menu
Courtesy of Hunter Engineering Company
Slotted Lower Control Arm
Courtesy of Hunter Engineering Company
Lower Strut Attachment
 Lower
attachment bolts
may permit
camber angle
adjustment.
 Aftermarket
kit
may be required.
Courtesy of Hunter Engineering Company
Upper Strut Plate
 Camber
and/or
caster may be
adjusted by
repositioning
the upper strut
mount
 Aftermarket
kit
may be required
Courtesy of Hunter Engineering Company
Ball Joint
A
ball joint
may be rotated
or repositioned
to adjust
camber and /
or caster.
Courtesy of Hunter Engineering Company
Strut Rod
 Loosen
one nut
and tighten the
other to adjust
caster
 Washers
may
also be used
Courtesy of Hunter Engineering Company
Bushing or Threaded Insert
 Camber
and / or
caster may be
adjusted by
rotating or
replacing the
insert bushing.
Menu
Courtesy of Hunter Engineering Company
Typical Rear Adjustments
Full Contact Shim
Eccentric Cam
Tie Rod
Lower Strut
Slotted Control Arm
Wedge
Strut Rod
Menu
Courtesy of Hunter Engineering Company
Full Contact Shim
 Adjust
Rear
Camber and
Toe using full
contact shims
 Hunter
 Northstar
 Specialty
Courtesy of Hunter Engineering Company
Eccentric Cams
 Eccentric
cams
may be used to
adjust rear toe
and /or camber
Courtesy of Hunter Engineering Company
Tie Rods
 Adjust
rear
individual toe
using tie rod
adjustment
Courtesy of Hunter Engineering Company
Lower Strut
 Rear
camber
may be
adjusted by
loosening the
lower strut
retaining bolts
and pulling
inward or
outward
Courtesy of Hunter Engineering Company
Slotted Control Arm
 Rear
lower
control
arms may
be slotted to
permit toe
and camber
adjustments
Courtesy of Hunter Engineering Company
Wedge
A
“wedge” be
used to adjust
rear camber
 Wedges
may
also be used to
adjust front
camber
Courtesy of Hunter Engineering Company
Strut Rod
A
rear strut rod
may be used to
adjust
individual rear
toe
Courtesy of Hunter Engineering Company
What Are Equipment
Manufacturers Doing To Help
Technicians Adjust Various
Control Arm Configurations
Faster And Better?
A
vehicle specific software tool has been
developed for vehicles with control arms
using shims, cams and slots.
Courtesy of Hunter Engineering Company
How to turn red bar graphs green fast
is the problem – adjust with shims
Courtesy of Hunter Engineering Company
Corvette with symmetrical A arm - shims
outboard of frame – actual shim size
Courtesy of Hunter Engineering Company
Caprice with symmetrical A arm - shims
inboard of frame – actual shim size
Courtesy of Hunter Engineering Company
Chevy C10 with asymmetrical A arm - shims
outboard of frame – actual shim size
Courtesy of Hunter Engineering Company
Chevy C10 with asymmetrical A arm - shims
outboard of frame – actual shim size
Courtesy of Hunter Engineering Company
Technician time saver – adjust one
side only to match the other side
Courtesy of Hunter Engineering Company
How to turn red bar graphs green fast is the
problem – adjust with eccentric cams
Courtesy of Hunter Engineering Company
Dodge B1500 van with eccentric cams - dual
bar graphs predict results – steer ahead graph
Courtesy of Hunter Engineering Company
Technician time saver – adjust one
side only to match the other side
Courtesy of Hunter Engineering Company
How to turn red bar graphs green fast is
the problem – adjust with dual slots
Courtesy of Hunter Engineering Company
Dodge B1500-3500 van with dual slots – dual
bar graphs predict results – steer ahead graph
Courtesy of Hunter Engineering Company
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