Specifications

17730-248 41 Alignment & Adjustments
AIRTEK
®
•
SOFTEK
®
for Blue Bird Buses
REAR AXLE AND REAR SUSPENSION
Rear axle misalignment can cause front tire wear. If the outer edge of one front tire is worn
and the inner edge of the other front tire is worn, check the following:
■
Make sure the rear axle (especially a tandem axle) is correctly aligned. Refer to the pro-
cedure from the manufacturer of the vehicle or the suspension.
■
All fasteners including U-bolts (if applicable) are installed and tightened to the speci-
fied torque.
■
The leaf springs are not worn or damaged.
■
The bushings in the leaf springs are not worn or damaged.
■
The torque rods (if used) are correctly adjusted (if adjustable).
■
The frame is not bent or twisted.
■
Refer to any additional recommendations and specifications from the manufacturer of
vehicle on rear axles and suspensions. Reference the TMC (The Technology &
Maintenance Council) Guidelines for Total Vehicle Alignment.
FRONT WHEEL ALIGNMENT
Hendrickson recommends technicians review TMC’s publication TMC (Technology &
Maintenance Council) “Guidelines for Total Vehicle Alignment”.
The AIRTEK/SOFTEK front wheel alignment specification can be found in the Appendix of this
publication.
Check the total vehicle wheel alignment when the following occur:
■
Every 80,000 to 100,000 miles, or 12-18 months (normal maintenance).
■
When the vehicle does not steer correctly.
■
To correct a tire wear condition.
■
There are two types of front wheel alignment:
1.
Minor alignment – a minor front wheel alignment is done for all normal mainte-
nance conditions, see below.
2.
Major alignment – a major alignment is done when uneven or excessive tire wear
is evident, or response at the steering wheel is sluggish, or the need for major
wheel alignment check and adjustment is required, see below.
MINOR FRONT WHEEL ALIGNMENT
Perform the minor front wheel alignment in the following sequence:
1. Inspect all systems that affect wheel alignment. Refer to “Inspection Prior to Alignment”
in this section.
2. Check the wheel bearing end play.
3. Check and adjust the vehicle ride height (for AIRTEK) as specified in the Preventive
Maintenance Section of this publication.
4. Check toe-in and adjust if necessary.
MAJOR FRONT WHEEL ALIGNMENT
Be certain to follow wheel alignment inspection intervals as specified by the original equip-
ment manufacturer. Before performing a major front wheel alignment it is recommended
that alignment equipment calibration be checked to ensure proper vehicle alignment.
SERVICE MANUAL
L
83
FRONT AXLE & SUSPENSION
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APPENDIX