MAHLE RTI Laser 4 - Manual (Page 2)

Page 2
EASY START GUIDE FOR THE TECHNICIAN
This is a guide for the practical and easy use of the Laser 4. Refer to the detailed sections of the
Operations Manual for more specific information.
I. Calibration
One of the main features of the Laser 4 is the precision calibration bar that can be used to easily ensure
that the instrumentation is always calibrated and accurate. In essence the calibration bar is made up
of two perfectly parallel end surfaces for checking the cross beam calibration and two parallel side
surfaces for checking the rear facing beam calibration. The beams are adjustable up and down and side
to side. The procedure is as simple as aiming the beam at the appropriate mirrored surface and then
aiming the mirror so the beam is reflected back in the exact same direction. It takes seconds.
II. Wheel Clamps
Another “quality” feature of the Laser 4 is the special wheel clamp. One highlight of the design is the
rotating feet that automatically align to the wheel. Another is the way in which run-out is
compensated. The rotating plates in the center of the wheel clamp have three adjustable legs to allow
for adjustment so that the plates are completely perpendicular to the axis of the wheel rotation (Like
leveling the legs of an appliance). Once set, the plate is always in the correct plane, no matter what
position the wheel is rotated. If adjusted and set on an aluminum wheel, additional compensation is
seldom required. Just rotate the wheel one revolution and be sure that the camber does not change
appreciably.
III. Camber
Camber is the amount the wheels lean in or out. It is checked with the electronic caster/camber gauge.
Most vehicles have negative camber and adjustment is seldom required unless the ride height of the
vehicle has changed. The important point to remember is that the camber on one side is supposed to
“cancel out” the “steering effect” of camber on the other side. If one side has more camber than the
other, the vehicle will pull to one side. The vehicle will pull to the side on which the wheel leans the
most outward or the least inward at the top.
IV. Caster
Caster is the amount of camber change when the wheel is steered out and then in a total of 30 to 40
degrees. (15 to 20 degrees out, 15 to 20 degrees in) It is checked with the electronic caster/camber
gauge, by zeroing the scale when turned out and then taking the reading when turned in. (Keep the
gauge level in both positions.) Like camber, the important point to remember is that the caster on one
side is supposed to “cancel out” the “steering effect” of caster on the other side. The vehicle will pull
to the side that has the least positive or most negative caster.
Caster and Camber can be adjusted within specifications to compensate for each other to eliminate
the tendency of the vehicle to pull to one side. Just because the caster and camber are within
specification does not mean the vehicle will go straight!