Specifications

17730-248 87 Component Replacement

AIRTEK

•

SOFTEK

for Blue Bird Buses

FIGURE 9-60 FIGURE 9-61

STEERING KNUCKLE BORE MEASUREMENT

Complete the following steering knuckle bore inspection and the measurement instructions

prior to installing the kingpin bushing.

1. Measure the upper knuckle bore inside diameter at two locations. Always use an inside

micrometer or a telescoping gauge when taking a knuckle bore measurement. Some

out-of-roundness at the top and bottom of the bore edges is acceptable. Steering

knuckle bore diameter is 1.938" ± 0.003"

2. Measure the upper and lower bore in two positions and at two locations. The two posi-

tions must be 90º opposed from each other, see Figures 9-62 through 9-64. If the

average measurement is more than the knuckle bore maximum diameter specification,

replace the knuckle.

FIGURE 9-62 FIGURE 9-63 FIGURE 9-64

KINGPIN BUSHING INSTALLATION

1. A hydraulic shop press with a minimum forcing capacity of 5 tons will be required.

BEFORE APPLYING HYDRAULIC PRESSURE TO ANY TOOLING SET-UP, ALWAYS CHECK TO BE

SURE THE PRESS PLATE, ADAPTERS, AND COMPONENTS BEING WORKED ON ARE

POSITIONED PROPERLY, I.E. “IN LINE” WITH THE RAM. IMPROPER POSITIONING CAN CAUSE

PERSONAL INJURY OR COMPONENT DAMAGE.

2. Install the lower or upper steering knuckle in the press.

3. Install the kingpin bushing from the machined side (axle side) of the lower steering

knuckle using a bushing driver, (see driver specifications in the Special Tools Section of

this publication). Press in bushing to a depth of no less than

" (0.236") or 6 mil-

limeters and no more than

" (0.32") or 8 millimeters, see Figures 9-65 and 9-67.

4. Following this procedure it is necessary to ream the kingpin bushings to fit the king-

pins, (see Kingpin Bushing Reaming Instructions).

SERVICE MANUAL

129

FRONT AXLE & SUSPENSION

APPENDIX