Document mqkazGer1B6w3zyXaLx9eG8BQ

1 (e) The lining consists of a dense, grayish material vitt curves of varying diameters. A typical front lininc 2 for a medium or heavy duty truck is 5/16 inch thickj 15-3/4 inches long, and 4 inches vide. Tvo such 3 linings would be used per drum. A typical rear lining is 1/2 inch thick, 8-5/8 inches long, and, 7 inches 4 vide. Four such linings would be used per drum. 5 A typical front lining for a bus would be 3/4 inch thick, 6 inches wide, and 7-1/8 inches long. 6 Four linings would be used for drum. A typical rear lining is 3/4 inch thick, 10 inches vide, and 7-1/8 7 inches long. Four linings would be used per drum. 8 Original equipment drum brake linings and shoe assemblies for medium and heavy duty trucks and for 9 buses are purchased either as part of a complete brake assembly or as part of an axle assembly. Engineering 10 information is obtained regarding these assemblies and usually not with respect to their hundreds of 11 components. Therefore, information is generally not available as to the markings on the brake linings not 12 manufactured by General Motors. 13 Identification of the suppliers of the brake linings for particular trucks and years would involve 14 an extensive search of engineering bills of materials, engineering parts lists, and purchasing records. 15 There are 120-150 rolls of microfilm of engineering bills of materials, 50 boxes of microfiche of 16 engineering parts lists, and 91 rolls of microfilm and 2091 microfiche of purchasing records at present. 17 From 1979 to present, the engineering parts lists are supplemented monthly and each supplement would have to 18 be checked to find any new brake/ assemblies. The process is further complicated because the medium and 19 heavy duty truck business is basically a "customized" business. Practically all heavy duty trucks and most 20 medium duty trucks are ordered to--precise customer specifications as to engine, transmission, axle 21 (including brakes), and other equipment combinations the operator requires. This means that there are 22 numerous regular production options as well as special equipment options created for particular customers. 23 Based upon a search of purchasing records, the 24 following outside suppliers of original equipment' brake assemblies and shoe and lining assemblies have 2.5 been identified for 1974 to 1989 (unless otherwise indicated): 26 Rockwell Brake Division Buses 27 Eaton Brake Division Medium & Heavy Duty trucks 26 Wagner Electric (1974-1982) Heavy Duty Trucks B. F. Goodrich (1974-1982) Heavy Duty Trucks 25