3
HOW IT WORKS
The TR-12 Series wheel alignment systems measure Caster, Camber, SAI, and Toe. Two-wheel,
Thrust angle (squaring or rear steer), and four-wheel can be done easily, with speed and accuracy.
These alignments can also be referenced to the mechanical centerline of the vehicle. Depending on
the type of vehicle being aligned, the technician chooses which alignment to do.
Although this manual presents standard two-wheel, thrust angle, and four-wheel alignment
procedures, other variations are possible. The procedures that have been laid out in the manual are
a guideline that is proven in the field. The technician can deviate from these procedures as
required.
All measuring gauges are mounted on the wheel clamps or hub adapters by hanging them on the
mounting disk, by doing if a clamp is dropped during mounting you will not damage the system
itself. The Easy Check Gauge is used to measure caster, camber and SAI on the front wheels as
well as a live caster adjustment. The two Laser Guns and two front Combi Gauges are used to
measure toe, and thrust angle (square ness or rear steer). The front Combi Gauges also measure
camber on the front wheels if the wheels only have plus or minus three degrees of camber.
Reading the Scales:
1) The toe scales are used to dial toe specifications into both Laser Boxes and both Combi
Gauges. Toe can be measured in millimeters, inches, or degrees. The toe scale is located on
the top of each Laser Box and Combi Gauge. The scale is used in conjunction with the toe
adjustment knobs and dial rings.
2) The Run-Out Scales are located on the Laser Gun Box Face. They are used in the Run-Out
procedure with the laser only.
3) The thrust angle scales are located on the Frame Centering Flags. The flags measure the
centering of the vehicle, and measure the angle of the rear axle (thrust).
4) The camber scales are located on the Easy Check Gauge and each Combi Gauge. Camber
can be measured on the four wheels.
5) The caster scale is located on the Easy Check Gauge. Caster is measured on the front
wheels. The bubble on the caster scale is adjusted with knob on the bottom right-hand
corner on the Easy Check Gauge. This scale is also used when performing run-out with the
caster / camber gauge and rim clamps.
6) The SAI scale & caster adjustment scale are located on the top of the Easy Check Gauge.
SAI is measured on the front wheels. The caster adjustment scale gives you the ability to
make a Live Caster Adjustment; the Easy Check Gauge should be locked in place with
either of these readings, which is done with the locking screw tightened onto the mounting
disk.
Note:
Diagrams are included in each section.
