Specifications

Preventive Maintenance 34 17730-248

AIRTEK

•

SOFTEK

for Blue Bird Buses

KINGPIN BUSHING INSPECTION

INSPECTION PROCEDURE (STEERING KNUCKLE LATERAL MOVEMENT)

1. Chock the wheels to help prevent the vehicle from moving. Set the parking brake.

2. Use a jack to raise the vehicle until the wheels are off the ground. Support the vehicle

with safety stands.

FIGURE 7-20 FIGURE 7-21

3. CHECKING THE UPPER KINGPIN BUSHING. Install the base of a dial indicator onto the

axle beam and face the tip against the steering knuckle, see Figure 7-20.

4. Set the dial indicator to “0” zero.

5. Move the top of the tire in and out by applying reasonable constant pressure and then

release, see Figure 7-22.

FIGURE 7-22

6. Check the reading on the dial indicator.

If the dial indicator moves more than

0.015", the upper bushing is worn or

damaged. Replace both bushings. Refer

to the Kingpin Bushing replacement pro-

cedure in the Component Replacement

Section of this publication.

7. CHECKING THE LOWER KINGPIN

BUSHING. Install a dial indicator so that

the base is on the axle and the indicator

tip is against the inside of the bottom of

the knuckle, see Figure 7-21.

8. Set the dial indicator to “0” zero.

9. Move the bottom of the tire in and out. If

the dial indicator moves more than

0.015", the lower bushing is worn or

damaged. Replace both kingpin bush-

ings. Refer to the Component

Replacement Section of this publication.

NOTE If one bushing is worn or damaged, it is mandatory to replace both the top and bottom

bushings on that knuckle assembly.

APPENDIX

SERVICE MANUAL