Laser 4 ® Laser 4 Plus ® OPERATION MANUAL Four Wheel Alignment RTI Technologies, Inc. York, PA 17402 800-468-2321 (Ext. 259) Manual No.
TABLE OF CONTENTS Four Wheel Alignment, Basics . . . . . . . . . . . . . . . . . . . 3 Pre-Alignment Checks . . . . . . . . . . . . . . . . . . . . . . . . . 4 Four Wheel Alignment Procedures Install Wheel Clamps . . . . . . . . . . . . . . . . . . . . . 5 Compensating Wheel Runout . . . . . . . . . . . . . . . 5 Camber Reading . . . . . . . . . . . . . . . . . . . . . . . . . 7 Caster Reading . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Steering Axis Inclination (SAI) Reading . . . . .
The Laser 4 Plus is a four-wheel alignment system that uses three Class II laser products. These lasers have a maximum output power of 5.0 milliwatts. The laser tubes meet all government safety standards, although common sense dictates that one should not stare directly into the beam. Laser precision is unaffected by light, temperature, and the concentrated light beam is clearly visible anywhere. The following precautions have been taken to insure the safety of the system (See Fig.
FOUR WHEEL ALIGNMENT Rear wheels must track and follow the front wheels in a parallel direction with all four wheel adjusted to the common centerline of the vehicle. (See Fig. 2) 1)Front wheel alignment and front wheel toe on car ma n u f a c t u r e r ’ s specifications. 2)Rear wheel alignment and rear wheel toe on car ma n u f a c t u r e r ’ s specifications. 3)Front wheels track to rear wheel thrust lines and to centerline of vehicle. 4)Steering wheel centered in straight ahead position.
PRE-ALIGNMENT CHECKS To maintain a true alignment job; ensure maximum tire mileage and steering safety, it is important to perform certain pre-alignment checks before doing wheel alignment adjustments. They are: 1. Inflate tires to proper inflation pressures. 2. Check car spring height. 3. Check shock absorbers and struts. 4. Inspect steering/suspension parts for wear or looseness. Replace parts which are worn beyond manufacturer’s accepted tolerances. 5.
INSTALL WHEEL CLAMPS Install Wheel Clamps on each wheel. (See Fig. 6) Adjust the four bars in each clamp for the best fit to the wheel rim. Two sets of notches on one end or a threaded pin on the other end provide for inside or outside mounting to the wheel rim. Use double-sided foam tape at contact points on decorative or soft metal rims. Make sure that the Wheel Clamps are securely attached. Select the configuration which gives the most secure fit with the least amount of pressure on the wheel rim.
COMPENSATING WHEEL RUNOUT (Laser 4) Wheel Clamps must be adjusted to compensate for wheel runout. This adjustment is made using the three Wheel Runout Adjusting Knobs. 1) Raise wheel and tire from turning gauge or rear wheel slip plate. Turn wheel so the large wheel clamping knob is at the top (12 o’clock position). 2) Mount the Spirit Level Gauge on the Wheel Clamp. (See Figure 9) Center the magnet on the Wheel Runout Compensating Adapter. Turn the Spirit Level Gauge so it is level.
CAMBER READING (Laser 4 Plus) Camber: The inward or outward tilt of the wheel at the top Camber is measured in degrees. Wheel exactly vertical: Zero camber Top of wheel tilts in: Negative camber Top of wheel tilts out: Positive camber A vehicle with Negative Camber is shown in Fig. 10. Proceed with the following steps to read Camber: 1) Place front wheels in straight ahead position with steering wheel level. The engine must be started if the vehicle has power steering.
Camber Reading (Laser 4) Proceed with the following steps to read Camber: 1) Place front wheels in straight ahead position with steering wheel level. The engine must be started if the vehicle has power steering. Remove locking pins from the turning radius gauges and rear wheel slip plates. Rotate each wheel until the large wheel clamp adjusting knob is at the top. 2) Lower all four wheels until the front wheels rest on the turning radius gauges and the rear wheels rest on the rear wheel slip plates.
CASTER READING (Laser 4 Plus) Caster: The backward or forward tilt of the ball joint or strut at the top Caster is measured in degrees: Spindle support arm straight up and down on the true vertical: Zero Caster Spindle support arm is tilted forward at the top from true vertical: Negative Caster Spindle support arm is tilted back at the top from true vertical: Positive Caster A vehicle with Positive Caster is shown in Fig. 15.
CASTER READING (LASER 4) Proceed with the following steps to read Caster: 1) With the Spirit Level Gauge mounted on the left front wheel clamp, turn the left front wheel outward at the front for a 20 degree reading on the radius gauge. (See Fig. 19) 2) Turn the Spirit Level Gauge so it is level. 3) Adjust the Caster bubble to zero with the adjusting knob on the bottom of the gauge. 4) Turn the wheel inward at the front for a 20 degree reading on the radius gauge. This is a total swing of 40 degrees.
STEERING AXIS INCLINATION (SAI) READING (LASER 4 Plus) SAI: The inward tilt of the ball joint or strut at the top . Proceed with the following steps to read SAI: 1) With the Electronic Gauge mounted on the left front wheel clamp, turn the left front wheel outward at the front for a 20 degree reading on the radius gauge. (Refer to Fig.19) 2) Turn the Electronic Gauge so it is level. 3) Set the selector to SAI and press the switch to ON. Press the Zero Button. (See Fig.
STEERING AXIS INCLINATION (SAI) READING (Laser 4) SAI: The inward tilt of the ball joint or strut at the top . Proceed with the following steps to read SAI: 1) With the Spirit Level Gauge mounted on the left front wheel clamp, turn the left front wheel outward at the front for a 20 degree reading on the radius gauge. (See Fig. 24) 2) Pivot the Spirit Level Gauge so that the SAI bubble reads zero on scale “L”.
INSTRUMENTATION SET-UP Center the Steering Wheel: Center the steering wheel in the straight ahead position and clamp in place with the Steering Wheel Holder. The engine must be running to set the steering wheel position on cars with power steering. Mount the Left & Right Laser Toe Gauges: 1) Determine the manufacturer’s preferred total toe specification for the front wheels. Rotate the tapered magnet on each Laser Toe Gauge to one-half this specified value. (See Fig.
FRONT WHEEL TOE READING Toe: The difference in distance between the front and rear of the front wheels Toe-in: Distance between front of wheels is less than distance between rear of wheels Toe-out: Distance between front of wheels is greater than distance between rear of wheels Adjust Laser Beam Mirror & Target: The Left Laser Toe Gauge projects a laser beam onto the right mirror (A). This beam is reflected back to the graduated toe scale on the Left Laser Toe Gauge.(See Fig.
TOE READING ILLUSTRATIONS Page 15
FRONT WHEEL ALIGNMENT VEHICLE CENTERLINE 1) Project the laser beams from the Left and Right Toe Gauges onto the Rear Retro-screens. If the beam does not strike the rear mirror, check the level of the Laser Toe Gauge. (See Fig. 32) 2) Note the readings on the scales of the rear screens. Add both readings and divide by two. 3) Adjust both tie rods or tie rod adjusting sleeves equally so that the rear screens register the desired reading determined in Step 2.
THRUST ANGLE ALIGNMENT 1) Check that both Laser Toe Gauges are level. The laser beams should be visible on the rear Retro-screen mirrors (See Fig. 35). 2) Rotate the rear Retro-screen assemblies out of level, if necessary, so that the laser beams will be reflected back to the front Toe Gauges and be visible on the Thrust Angle Scales. 3) Note the readings on the Thrust Angle Scales. Add both readings and divide by two.
Total Vehicle Four-Wheel Alignment 1) Check that both Laser Toe Gauges are level. The laser beams should be visible on the rear Retro-screen mirrors.(See Fig. 38) 2) Rotate the rear Retro-screen assemblies out of level if necessary, so that the laser beams will be reflected back to the front Toe Gauges and be visible on the Thrust Angle Scales. 3) Note the reading on each of the Thrust Angle Scales.
CALIBRATION PROCEDURE Mount and level the Calibration Bar on Calibration Stands or the rear of the Storage Cart Calibration of Front Wheel Toe Laser Beam (See Figure 42) 1) Rotate the tapered magnets on the Left and Right Toe Gauges to zero. 2) Mount the Left and Right Toe Gauges on the ends of the Calibration Bar. Be sure the centers of the magnets fit over the raised machined surfaces at the ends of the Calibration bar. (See Fig.
CALIBRATION PROCEDURE The Gauges are now parallel - “Toe reads zero” Calibration of Right & Left Toe Gauge Laser Beams 1) Rotate all tapered magnets on the Toe Gauges and Rear Retro-screens to zero 2) Mount the Left Toe Gauge and Left Retro-screen to the machined surfaces on the side of the Calibration Bar. (See Fig.
CALIBRATION PROCEDURE Calibration of Right & Left Toe Gauge Laser Beams (continued) 3) Level the Toe Gauge and project the laser beam image on the rear Retro-screen. (See Figure 44) The center of the beam image must be on 6 and midway up the mirror. If not, alternately loosen and tighten Allen set screws on the laser diode retainer. There are four Allen set screws on the laser diode retainer. (See Figure 45) The top and bottom set screws (D) control the vertical movement of the beam image.
BATTERY REPLACEMENT The Laser 4 is powered by eight “C” batteries; four batteries located in each Toe Gauge. Alkaline batteries are recommended for extended life. The batteries should be replaced when the laser beam image becomes dim or can no longer be seen. To replace the batteries (See Figure 46): 1) Flip the Laser Toe Gauge switch to OFF. 2) Place the Laser Toe Gauge on a workbench with the underside of the casting facing up. 3) Loosen the battery cover locking knobs and open the cover.
