AXLE ALIGNMENT ZF (40 FT)

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Owen Jackson
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1 SECTION / DE06 GENERAL CONDITIONS See Figures 1 and 2 for the geometry of the frontand rear axles. Figure 3 represents the axis system of a Nova LFS 40-ft bus. Before performing the alignment, the following conditions must be met: 1. Inspect the following points on the vehicle: a. Make sure tire inflation is correct. See section 06: wheels and tires, for additional information. b. Check the wheel installation and out-of-round wear. c. Check wheel-bearing adjustment. d. Check the tightness of all steering and axle joints. 2. Make sure that the bus is level. If necessary, level the vehicle according to the procedure found in section 08: kneeling and leveling. 3. Perform a road test. 4. Park the vehicle on a level and solid surface. 5. Put the transmission in the neutral position with the parking brake applied. 6. Connect an air supply to the external connector(s) of the vehicle. (X=-111, Y=662, Z=651) X 0.0 (X=111, Y=662, Z=651) LEVELING HEIGHT OF 4 FRONT AIR SPRINGS (295.1) CENTRAL AXIS OF WHEELS - LEVELING POSITION Z 0.0 Figure 1 - Front Suspension Geometry

2010DE06 2 /04-000.10 X -6197 (X=-6930, Y=1014, Z=332) (X=-5465, Y=1014, Z=332) (X=-6902, Y=805, Z=190) LEVELING HEIGHT OF 4 REAR AIR SPRINGS (228.7) Z 0.

2 2010DE06 2 / X (X=-6930, Y=1014, Z=332) (X=-5465, Y=1014, Z=332) (X=-6902, Y=805, Z=190) LEVELING HEIGHT OF 4 REAR AIR SPRINGS (228.7) Z 0.0 (95) CENTRAL AXIS OF WHEELS - LEVELING POSITION (887.5) WITHOUT DISK WEAR (841.5) WITH DISK WEAR 3 Y (887.5) WITHOUT DISK WEAR (841.5) WITH DISK WEAR CENTRAL AXIS OF WHEELS - LEVELING POSITION TRAVEL IN EXTENSION (85) (532.5) (532.5) TRAVEL IN EXTENSION (85) (97) TRAVEL IN COMPRESSION (85) TRAVEL IN COMPRESSION (85) Z 0.0 (185) GROUND CLEARANCE (X=-5465, Y=-1014, Z=332) (X=-5465, Y=1014, Z=332) (X=-5492, Y=-805, Z=190) (X=-5420, Y=-485, Z=180) (X=-5492, Y=805, Z=190) (X=-5419, Y=485, Z=180) (X=-5416, Y=-450, Z=104) (X=-5416, Y=450, Z=104) Figure 2 - Rear Suspension Geometry

3 / DE06 Y 0.0 Z 0.0 (+) X 0.0 Y 0.0 Z 0.0 Z AXIS Y AXIS (+) Z AXIS (+) X AXIS (-) (-) FRONT (-) (+) FRONT AXLE Y AXIS: theoretical axis of the vehicle passing through the front center and rear center of the structure. Y POSITIVE: toward the street side of the vehicle. Y NEGATIVE: toward the curb side of the vehicle. X AXIS: front axle center. The rear axle center position is also measured in relation to this axis. X POSITIVE: toward the front of the vehicle. X NEGATIVE: toward the rear axle. Z AXIS: height of the vehicle. Z POSITIVE: toward the roof of the vehicle. Z NEGATIVE: toward the roadway. REAR (-) REAR AXLE Figure 3 - Axis System ALIGNMENT PROCEDURE Axle alignment of a Nova LFS must be performed in the following order: 1. Rear axle alignment 2. Rear axle inclination 3. Drive shaft angle 4. Front axle alignment 5. Camber check 6. Caster adjustment 7. Toe adjustment 8. Steering wheel position adjustment The vehicle operator is at liberty to choose the type of equipment and alignment procedures that best suit the circumstances. However, the results should not differ. CAUTION: Be sure to perform a complete alignment of the vehicle according to specifications. CAUTION: To obtain proper readings, ensure the assembly and equipment are appropriate. If the assembly and equipment are not appropriate, readings and results will be inaccurate. CAUTION: Whenever shims are added, or removed, from the radius rods to adjust the alignment of the axles, ensure that the shims are distributed equally on each side, since torsion of the axle causes premature wearing of the bushings on the radius rods. The thickness of the added shims must be a maximum of 1/4 in. (6 mm) per adjusted face. There must always be at least one shim of 1/8 in. (3 mm) thickness between the radius rods and the structure. Once the shims are installed, tighten the radius rods to the torques indicated in section : radius rods in this manual. CAUTION: For all non-specified torque values, see sections 04: zf front axle and 05: zf rear axle in this manual.

4 2010DE06 4 / REAR AXLE ALIGNMENT The alignment of the rear axle allows verification of whether the rear axle is perpendicular to the longitudinal axis of the structure (W axis perpendicular to the Y axis). See Figures 3 and 4. If the value obtained exceeds the tolerance indicated in Figure 4, adjust by adding or removing shims at the attachment points of the upper radius rods only. REAR AXLE INCLINATION The inclination of the rear axle allows for the drive shaft to be aligned between the rear axle output and the transmission output according to an axis. See Figure 5. To measure this angle, place a digital protractor with a precision of 0.1 o on any 90º machined surface, or the air spring support plates. If the latter are used, ensure that they are leveled to 0º. See Figure 5. The reading of the angle must be between 80.5º and 81º. Adjust by adding or removing shims at the attachment points of the lower radius rods only. The shims must be distributed equally on each side. Recheck the measurement of the angle after having added or removed the shims. DRIVE SHAFT ANGLE To measure this angle, place a digital protractor with a precision of 0.1º on the machined surface of the drive shaft, as shown in Figure 6. The value must be between 6.8º and 11.1º. FRONT AXLE ALIGNMENT The alignment of the front axle allows the placing of the front axle perpendicular to the longitudinal axis of the structure (X axis is perpendicular to the Y axis). See Figures 3 and 4. If the value obtained exceeds the tolerance indicated in Figure 4, adjust by adding or removing shims at the attachment points of the upper radius rods only. THE AXIS X 0.0 MUST BE PERPENDICULAR TO THE AXIS Y 00 X-Y = <3MM X X 0.0 (X=675, Y=315, Z=126) (X=502, Y=606, Z=-274) 3 TOLERANCE OF PERPENDICULARITY OF FRONT AXLE 3 3 TOLERANCE OF PERPENDICULARITY OF REAR AXLE Y REAR AXLE (X=502, Y=606, Z=274) (X=675, Y=315, Z=-126) FRONT AXLE Figure 4 - Rear Axle and Front Axle Alignment

5 / DE06 DIGITAL PROTRACTOR (TYPICAL) LEVELED TO 0º PLACE ON ANY 90 MACHINED SURFACE OR ON THE AIR SPRING SUPPORT PLATES (LEVELED TO 0 ) Figure 5 - Rear Axle Inclination POSITIVE CAMBER LOADED 8.5 KNUCKLE SUPPORT (+0.67) (-0.67) NEUTRAL Figure 6 - Measuring the Drive Shaft Angle CAMBER CHECK This verification allows to see if the tire axis is oriented according to the X-axis (see Figures 2 and 7), with a right and left angular tolerance of: Left side: Right side: o to o o to o The measurement of the camber is for verification purposes only. The camber cannot be adjusted. For the above operation, the vehicle must be free of any load and the axle alignment process must be completed. Camber and caster must be carried out simultaneously ROLLING RADIUS OFFSET Figure 7 - Camber Adjustment

6 2010DE06 6 / CASTER ADJUSTMENT This adjustment allows for the steering column axis to be set at a predetermined angle, or in other words, to align the front wheels according to the X-axis. See Figures 3 and 8: Left side: 3.5 o ± 0.17 o Right side: 3.5 o ± 0.17 o If the reading is not within the indicated range, adjust the alignment of the front axle by adding shims only to the lower radius rods. Add the shims equally to both sides, since torsion of the axle causes premature wearing of the bushings on the radius rods. If it is not possible to obtain the desired value of one of the sides, the upper radius rods can be used to compensate. TOE-IN ADJUSTMENT The toe-in value is the difference between the distance measured between the front of the left-side rim and the front of the right-side rim of the front axle (value U) and the distance measured between the rear of the left-side rim and the rear of the right-side rim of the front axle (value V). See Figure 9. The toe-in value must be between + 1 /32 in. (0.8 mm) and + 1 /16 in. (1.6 mm). The settings must be adjusted at the tie rod. STEERING WHEEL POSITION ADJUSTMENT This adjustment allows to align the steering wheel in its neutral position. See section : steering column for the procedure. 3.5 ±0.17 SWIVEL AXIS OF KING PIN KNUCKLE SUPPORT KING PIN KNUCKLE (X2) Figure 8 - Caster Adjustment

04-000.10/ 7 2010DE06 REAR OF FRONT WHEEL FRONT OF FRONT WHEEL THE TOE IN MUST BE Z=(V-U)=+0.8MM À +1.6MM TOE IN =(V-U)=Z+ TOE OUT =(V-U)=Z- TIE ROD V U V 1810 MM U Y 0.

7 / DE06 REAR OF FRONT WHEEL FRONT OF FRONT WHEEL THE TOE IN MUST BE Z=(V-U)=+0.8MM À +1.6MM TOE IN =(V-U)=Z+ TOE OUT =(V-U)=Z- TIE ROD V U V 1810 MM U Y 0.0 REAR OF FRONT WHEEL FRONT OF FRONT WHEEL WHEEL TOE IN = V U X 0.0 Figure 9 - Front Axle Toe-in STEERING ANGLE ADJUSTMENT See Figures 10 to 13. This adjustment allows to adjust the front axle stroke-end stops to avoid having to readjust the power steering needle valves. The stops limit the maximum left and right steer angle by absorbing residual energy in the power steering after pressure is cut from the power steering gearbox. See Figure 10. ATTENTION : Before adjusting the steering angle, check if the air pressure in the pneumatic suspension is adequate and ensure that the front axle is properly aligned. ATTENTION: Before adjusting the steering angle, see section 07: steering mechanism in this manual. Make sure that the pitman arm is properly installed on the steering mechanism and that the drag link is adjusted properly and that it is neither twisted nor bent. STOP BOLT Figure 10 - Stop Bolt Under Front Axle

8 2010DE06 8 / Lift the front of the bus until the front end is raised off the ground. See section 18: hoisting and towing in this manual for more information. 2. Adjust the right stop bolt: a. Measure the distance between the top of the bolt head and the surface of the axle. b. If necessary, unscrew the stop bolt until the top of the bolt head is at a distance of 48 mm from the surface of the axle. See Figure 11. c. Turn the steering wheel to the right, as far as possible, while keeping in line with the following steering angles. See Figures 12 and 13. Left side: 36 o +1 o /-2 o Right Side : 45 o, +1 o /-2 o When adjusting the stop bolts, ensure that at the end of the turning cycle (full steering lock), a minimum allowance of 3/4 in. (19 mm) between the side of the tire and the air spring is respected. During the adjustment process, the maximum pressure should never exceed 90 N m, thus preventing damage to the system. (50 TO 70 LB-FT (70 TO 90 N M) STEERING ANGLE 48 MM LOCKNUT STOP BOLT SHIM 1/8 TO 3/16 IN. Figure 11 - Stop Bolt Adjustment Figure 12 - Stop Bolt at Maximum Steering Angle 45 O A 36 O 45 O B 36 O Figure 13 - Steering Angle Adjustments

9 / DE06 3. Adjust the left stop bolt: a. Measure the distance between the top of the bolt head and the surface of the axle. b. If necessary, unscrew the stop bolt until the top of the bolt head is at a distance of 48 mm from the surface of the axle. See Figure 11. c. Turn the steering wheel to the right, as far as possible, while keeping in line with the following steering angles. See Figures 12 and 13. Left side: 45 o, +1 o /-2 o Right Side : 36 o, +1 o /-2 o 4. After these adjustments, always check that the wheels have clearance relative to the suspension, brakes and structure. If the steering wheel is difficult to turn after these steps, check the connections and pressure from the hydraulic and steering systems.

10 2010DE06 10 / TROUBLESHOOTING GUIDE PROBLEM CAUSE SOLUTION Tires wear quickly or unevenly Bus is difficult to steer Worn out tie rod ball joint Broken or bent drag link, pitman arm or drag link arm Worn out or damaged ball joint stud Worn out pivot or bearings Vibration or floating in front axle, while the bus is moving 1. Incorrect front wheel toe-in adjustment 2. Incorrect tire pressure 3. Unbalanced tires 4. Incorrect steering arm geometry 1. Low pressure in power steering 2. Steering mechanism incorrectly assembled 3. Steering linkage needs lubrication 4. Jammed pivot 5. Incorrect steering arm geometry 6. Misadjusted caster angle 7. Hard to shift ball joints 8. Damaged thrust bearing 1. Ball joints need lubrication 2. Difficult operating conditions 3. Damaged ball joint cap 4. Power steering cylinder installation is incorrect 1. Too much pressure in power steering 2. Misadjusted cutting pressure of power steering 3. Bus does not function properly 4. New power steering incorrectly installed 1. Torque on drag link fitting exceeds specified torque 2. Lack of lubrication or bad type of lubricant 3. Misadjusted power steering stops 1. Worn or missing seals 2. Inappropriate lubricant 3. Linkage is not lubricated at the appropriate frequency 4. Incorrect lubrication procedure 5. Lubrication program does not correspond to normal operating conditions 1. Misadjusted caster 2. Unbalanced wheels or tires 3. Worn out shock absorbers 1. Adjust front wheel toe-in 2. Adjust pressure according to indicated specifications 3. Balance or replace tires 4. Proceed with steering mechanism maintenance 1. Repair power steering 2. Assemble steering mechanism properly 3. Lubricate steering linkage 4. Replace pivot 5. Proceed with steering mechanism maintenance 6. Adjust caster angle 7. Replace ball joints 8. Replace thrust bearings 1. Lubricate ball joints. Ensure that lubrication program is respected 2. Operate bus under normal conditions 3. Replace cap 4. Install power steering cylinder correctly 1. Adjust power steering pressure according to specifications 2. Adjust pressure in power steering according to specifications 3. Ensure that bus functions correctly 4. Install new power steering correctly 1. Apply a torque to the drag link according to specifications 2. Lubricate linkage with a specified lubricant 3. Adjust stops according to specified sizes 1. Replace seals 2. Lubricate linkage using suitable lubricant 3. Lubricate linkage at the correct frequency 4. Use adequate lubrication procedure 5. Adjust your lubrication program so it meets requirements for normal operating conditions 1. Adjust caster 2. Balance or replace wheels or tires 3. Replace shock absorbers Table 1 - Troubleshooting Guide

SECTION ZF FRONT AXLE

SECTION ZF FRONT AXLE 04-101.01/ 1 2011JA14 SECTION 04-101.01 6 3 5 1 2 9 1. Upper radius rod 2. Lower radius rod 3. Caliper 4. BRAKE Disk 5. Pneumatic connector 6. Hub 7. steering knuckle 8. Grease Fitting 9. Pneumatic connector