Specifications

17730-248 37 Preventive Maintenance

AIRTEK

•

SOFTEK

for Blue Bird Buses

FRONT HANGER/REAR SHACKLE BRACKET SURFACE PAINT WEAR

The Hendrickson front suspension systems AIRTEK and SOFTEK equipped on Blue Bird

buses, utilize rubber bushings in the leaf springs. These rubber bushings allow the leaf

spring to deflect and contact the front hanger and shackle plates when the bus encounters

high lateral acceleration (ex. a highway clover leaf). The rubber bushing will center the leaf

spring between the legs of the hanger/shackle plates once the vehicle is driven straight.

This function of the rubber bushing may allow the leaf spring to contact the front hanger/rear

shackle plate and possibly remove surface paint from the contact area. Surface paint wear

does not cause damage that will affect the function or durability of the front hanger/rear

shackle plate or their mating components provided a minimum wall thickness is maintained.

FIGURE 7-25

FIGURE 7-26

An indication that the front hanger/ rear

shackle plates are worn and require

replacement is when the components no

longer meet the following minimum

requirements:

■

Front hanger inboard leg minimum

thickness of 9.15 mm and the out-

board leg thickness minimum

thickness 11.00 mm, see Figure 7-

26.

■

Rear shackle plate minimum thick-

ness of 5.8 mm, see Figure 7-26.

SERVICE MANUAL

FRONT AXLE & SUSPENSION

APPENDIX