MEASURING PROGRAM 1–OBJECTIVES WORKSHEET
Module 1–Point-To-Point Measuring
A-2
A-8
Types of measurements commonly used to
When using tram gauges to make point-to-point
measure vehicles include:
measurements:
• ___________________________, which ref-
• set pointers at __________ heights when
using the tram gauge scale. This is important
erences length, height, and width.
since pointers set at different heights ________
• point-to-point, which is the distance between
________ provide the same reading on the
two points.
tram gauge as pointers set at the same height.
• insert the pointers securely into reference
A-4
A tape measure:
holes or on top of fasteners. When measur-
• is often used for making point-to-point mea-
ing to or between fasteners, measure from
the ____________ of the fastener head.
surements.
• should have the end ground down to fit
reference holes.
• must lay ________ between points.
A-9
If pointers are set at different heights to avoid an
obstruction, a tape measure should be used to
A-5
measure between the tips of the tram gauge
A tram gauge:
extensions.
• is a telescoping measuring device with adjustable pointers on each end. It is used for
Tram gauge pointers set at different heights to
making point-to-point measurements.
make datum measurements generally does not
• may require a ________ _______________to
measure between the pointers.
provide accurate results since it is difficult to
determine if the gauge is exactly parallel to the
datum plane.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
MEA01-STHO01-E
1
B-1
Point-to-point measurements for:
• holes of the same size are made either_______-to-_______ or center-to-center.
• fasteners will typically be center-to-center.
B-3
Diagonal measurements can measure to proper
specification even if the body structure is out of
alignment. This can be a problem if other dimensions are not referenced during point-to-point
measuring. Measuring __________ and
__________ in addition to the diagonal measurement will help ensure that the section is square.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
2
MEASURING PROGRAM 1–OBJECTIVES WORKSHEET
Module 2–Three-Dimensional Measuring
A-3
B-2
Vehicles are generally comprised of three sec-
A datum plane:
tions – _________, __________, and ________.
• is an imaginary surface or plane positioned
beneath the vehicle that is ______________
to the vehicle underbody.
A-4
The center section:
• is used by measuring systems as a starting
• is the __________________ of measuring.
point from which ____________ is measured
• is generally measured __________.
to various reference points on the vehicle.
• if undamaged, provides a reference for all
• distance from the bottom of the vehicle
varies according to the maker of the measur-
other measurements.
ing system or dimension guide.
__________ undamaged measuring points are
required to establish a foundation for measuring.
B-3
Centerline plane is:
B-1
• an imaginary plane that cuts the vehicle in
Three-dimensional measuring systems measure
half from the floor to the roof, running from
each reference point for length, height, and
front to rear.
width simultaneously. Length is measured from
a zero plane, height is measured from a datum
plane, and width is measured from a centerline
plane.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
• used by measuring systems as a starting point
from which ___________ is measured.
• used to establish a width position for vehicle
reference points.
1
B-4
C-2
Zero plane is:
Point-to-point measurements are ____________
• used by measuring systems as a starting point
than three-dimensional measurements when the
from which ___________ is measured.
two points being measured are not equal dis-
• an imaginary plane that extends across the
tances from datum, centerline, or zero plane.
width of the vehicle.
• projected at different locations depending
on the maker of the dimension guide.
C-3
Self-centering gauges:
• are used to identify __________________
B-5
misalignment.
Length measurements:
• are used to identify datum misalignment.
• may be identified by referencing a dimension
• have adjustable vertical scales for setting the
guide or identified on a computerized mea-
centering gauge at the correct datum height.
suring system.
• may
be
made
____________
or
_______________ of the zero plane.
• are made on the upperbody and underbody.
C-4
Centering gauges are:
• installed in sets of four or five.
• viewed from the front or rear of the vehicle.
C-1
• viewed against other gauges, not the floor or
When making three-dimensional measurements:
rack.
• height is measured _____________________
to the datum plane.
• length is measured ________________ to the
centerline and datum plane.
• width is measured perpendicular to the
Datum misalignment is indicated by the front or
rear section gauges being higher or lower compared to the two gauges in the center section of
the vehicle.
_______________ and parallel to the datum
plane.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
2
C-8
C-18
Self-centering gauges are not designed to mea-
An electromechanical measuring system:
sure a vehicle’s ______________. This requires
• uses a _________________ _______ with a
length to be measured with a tape measure or
pointer located under the vehicle that slides
tram gauge.
along a bridge or ladder positioned centrally
beneath a vehicle.
C-11
A universal mechanical measuring system:
• has adapters for the arm for different types
and sizes of reference points.
• uses a ___________ or _____________ posi-
• uses a computer program to receive the data
tioned under the vehicle to measure length.
sent to the computer from the mechanical
• measures width using the scale on the width
gauge.
• measures height using the scale on the height
tube.
arm.
• can be used to make continual measurements by leaving the pointer at the reference
point while making pulls.
C-14
C-21
A universal laser measuring system:
A computerized laser measuring system:
• uses a laser beam and measuring scales or
• has ______________ hung at reference points
_______________ in place of mechanical
that reflect light back to a hub (sensor) in the
pointers.
laser unit.
• may be a single laser unit using measuring
bars, gauges, and/or transparent targets.
• has adapters for hanging targets at different
types and sizes of reference points.
• may use a beam splitter to target multiple
gauges and bars simultaneously.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
3
C-24
C-27
Ultrasonic measuring systems:
A fixture system uses ___________ beams, or
• have ____________ hung at reference points
transverse beams:
that produce ultrasonic signals that are received by the measuring beam. The beam
processes and converts information into measurements.
• use a computer program to receive the data
• bolted to the bench at locations listed on a
fixture diagram.
• that have reference marks to accurately position fixtures.
• to mount fixtures at a specific location.
sent to the computer from the measuring
beam.
• have adapters for hanging probes on different types and sizes of reference points.
Fixture systems:
• have vehicle-specific reference manuals that
provide exact locations for mounting fixtures
to the bench.
• use a two-post hoist to load the vehicle on to
the bench.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
4
MEASURING PROGRAM 1–OBJECTIVES WORKSHEET
Module 3–Vehicle Dimension Data
A-4
A-7
Specifications that show the width measure-
Symmetrical measurements are the same on
ment in relation to centerline may be added
each side of the vehicle. Asymmetrical vehicles
together to get a _______________________
may have:
measurement.
• __________________ _________________
from the left to right side.
• reference points that are in different loca-
A-5
Items shown on a dimension sheet for the
tions.
underhood area may include measurements that
are:
A-10
• point-to-point.
If a vehicle is mounted in pinchweld clamps or
• referencing centerline.
lifted on a hoist, the front and rear of the vehicle
may sag if the weight is removed from the
Upperbody measurements listed in dimension
vehicle’s suspension; therefore, measurements
manuals:
may be listed as loaded or unloaded. A
• are generally point-to-point.
___________ measurement is taken with the
• may use reference points such as _________
drivetrain installed. An ________________ mea-
___________ and/or seams.
surement is taken with the drivetrain removed. A
removed drivetrain reduces the amount of sag in
A-6
the vehicle when it is not resting on its suspen-
Dimensions are:
sion.
• shown from either the _________ looking
down or the bottom looking up.
A-11
• provided in ____________________.
__________________ measurements may also
• symmetrical or asymmetrical.
be listed with the suspension loaded or unloaded. This affects the measurements to movable parts such as ball joints.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
1
B-3
E-1
The location of the zero plane and datum are
Vehicle repair tolerance:
provided in the manual. It is written as a specific
• is generally ±_____ mm for unibody vehicles.
distance and point. For example, datum may be
• is generally ±_____ mm for body-over-frame
listed as 300 mm below the rocker panel lower
flange edge.
vehicles.
• may be less for proper panel fit and suspension and drivetrain alignment.
D-1
Comparative measurements:
E-2
• allow _________________ measurements to
Tolerance applies to individual measurements or
covers a span of measurements. It cannot, how-
be made.
ever, be added to each measurement taken
• may be taken side-to-side.
• are
used
with
a
vehicle
that
is
_________________.
between two points. For example, five measurements are made between a point in the front of
• may be point-to-point.
the vehicle and a point in the rear of the vehicle.
• may be taken using three-dimensional mea-
Each measurement is off by 3 mm. While each
suring equipment.
individual measurement is off by 3 mm (within
tolerance), the overall misalignment is 15 mm.
D-2
This number is not within tolerance.
Measurements may be taken from an identical
undamaged vehicle. Generally, these are limited
E-3
to ________________________ measurements.
Tolerances of ±3 mm for unibody and ±5 mm for
body-over-frame vehicles apply to specifications
in each ____________.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
2
MEASURING PROGRAM 1–OBJECTIVES WORKSHEET
Module 4–Types Of Damage Conditions
A-3
A-6
Diamond is damage that occurs in the center
Sag is a condition where the front or rear sec-
section where one side is moved _____________
tions of the vehicle have __________ measure-
or ________________, causing the center sec-
ments that are out of specification. Sag may also
tion of the frame to be out of square, taking on
be a condition where the front or rear of the
a diamond-like appearance.
vehicle appear out of level.
A-4
A-7
Diamond:
Mash, also called collapse or short rail, is a
• may be determined by cross-checking diago-
condition where any section or frame member is
nal dimensions of the center section in addi-
_____________ than factory specification.
tion to making length, height, and width
measurements.
• is commonly associated with full frames.
A-8
Sway occurs when collision energy forces a part
of the vehicle to one side or the other. This
A-5
condition is a width misalignment.
Twist is damage that occurs to the vehicle center
section in which one or both ends of the center
section are _______ _____ _________ with each
other.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
1
MEASURING PROGRAM 1–OBJECTIVES WORKSHEET
Module 5–Preparing To Measure A Vehicle
A-2
A-6
Points used to measure vehicles are reference
A second type of measuring is measuring for
points. These points may be any particular area
vehicle repair. Measuring for repair:
on a vehicle that the technician uses to make a
• helps create a ___________ ___________
_______.
measurement.
• allows monitoring __________________ during straightening operations.
A-4
Measuring for damage analysis:
• requires the vehicle to be anchored to a
bench, rack, or floor to hold the vehicle in
• is done to locate _______________ and
place during straightening operations.
_______________ structural damage.
• is done to locate hidden damage.
• helps determine the repair plan.
B-1
A worksheet with illustrations:
A-5
• is helpful when using a system that does not
Equipment used for damage analysis should
provide an electronic readout of vehicle mea-
allow quick measurement of the vehicle to lo-
surements.
cate damage. Some measuring systems have
• helps to visualize the ____________ and
______________ of the damage.
special equipment designed to work with lifts to
create quick measurements. This eliminates the
need to mount a vehicle to a bench or rack to
B-2
obtain vehicle dimensions.
A worksheet with illustrations:
• helps develop an ________________ and
_____________ plan.
• assists the technician in monitoring the
straightening progress.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
1
B-3
A worksheet with illustrations may be used if:
• there are measurements that need to be
taken and no dimension specifications exist.
• measurements must be taken to movable
points.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
2
MEASURING PROGRAM 1–OBJECTIVES WORKSHEET
Module 6–Vehicle Measuring
A-3
A-5
To determine center section alignment, dimen-
To prevent interference when accessing refer-
sions that must be measured include:
ence points, proper anchoring locations may be
• diagonal.
identified on ______________ ____________.
• length.
Anchoring may or may not be necessary for
• height.
damage analysis depending on the type of mea-
• width.
suring system being used.
The established center section determines the
When anchoring vehicles:
zero line, width, and datum from which all other
• remove
_____________
and
__________________from the pinchweld
measurements will be based.
flanges and clamp jaws before installation.
A-4
• make sure that fuel and brake lines, cables,
Measuring the center section generally requires
hoses, or wires will not be crushed when
measuring the ________ corners of the center
installing pinchweld clamps.
section. For electronic measuring systems, this
establishes the centerline plane, datum plane,
A-6
and zero plane from which all other measure-
If the center section is damaged, it may be
ments are based.
necessary to work from an undamaged section
of the vehicle and work into the damaged area.
However, depending on the measuring system,
only ________ or __________ undamaged points
are required to make measurements. This may
require some preliminary pulls to align the center
section.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
1
B-2
C-5
When determining the basic reference points to
Another angle that is affected by SAI is camber.
be measured:
Camber is the ________________ and
• identify _______ __________ in each of the
_______________ tilt of the tire at the top com-
vehicle’s three sections.
• measure areas of obvious ___________ and
pared to true vertical when viewed from the
front of the vehicle.
_____________ damage.
The line of the upper and lower pivot point when
B-4
viewed from the side is called ____________.
Special adapters are often required to measure
The pivot point positions are verified by length
a vehicle’s ________________. Some systems
measurements from zero plane. Generally these
use devices similar to strut tower gauges that
measurements are comparison measurements
project upperbody damage below the vehicle.
only.
C-3
C-6
Steering axis is the imaginary line that projects
Points measured to determine proper caster
from the __________ pivot point through the
angles include the:
__________ pivot point on a wheel that is steered.
• upper strut pivot point to the ________ plane
This axis is critical to the performance of the
suspension system.
for the right and left side.
• lower ball joint to the ________ plane for the
right and left side.
The upper pivot point on a:
• MacPherson strut system is the strut bearing
These measurements may be comparative or
at the strut tower and the lower pivot point is
have specifications depending on the measuring
the lower ball joint.
system or reference material being used.
• short arm/long arm system is the upper control arm ball joint and the lower pivot point is
C-7
the lower ball joint.
To determine SAI angles, measure:
• solid axle system is the upper ball joint and
the lower pivot point is the lower ball joint.
• the ___________ pivot point to the vehicle
centerline for the right and left side.
• from the ________ ___________ to the vehicle to centerline for the right and left side.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
2
C-8
E-1
Measurements may be made to verify correct
Determine if the readings are consistent with the
position of steering rack, rear axle, engine cradle,
collision damage. If the readings are not consis-
etc.
tent, determine where the discrepancies exist.
D-1
E-2
Systems that use upper strut tower gauges may
Compare the measuring results against the
also use these gauges to make comparative
____________ damage. This verifies that the
measurements on both the vehicle center sec-
damage is consistent with the readings.
tion and the deck lid area. Hanging the gauges at
specified areas on the vehicle will determine if
E-3
the areas are symmetrical from side-to-side.
To determine if the readings made with a computerized measuring system are correct, com-
D-2
pare point-to-point measurements with mea-
Upperbody door opening measurements:
surements taken with a _________ ___________
• are generally point-to-point measurements.
or tape measure.
• are provided in dimension manuals.
• may be comparative from side-to-side.
D-4
Additional upperbody measurements:
• are generally point-to-point measurements.
• may include any upperbody point on a vehicle as long as it is a ____________________
point.
• may be provided in dimension guides.
• may be comparative readings from side-toside.
Measuring Program 1 v.3.2
© 2001 Inter-Industry Conference On Auto Collision Repair
3