CHAlRT lNFOFtMA TlOlN Pil lGES CHART DlES lGiN The charts are designed to list all lltems which are dletails of the Major Assemblies listed numerically at the top of the chart pages Major Groups may contain more than one chart Please note each chart has a description header which identifies the major assemblies listed and the text gr oup they are found in example Wheels Front Dlrurn Hub Wheel EEl 307 The text group lists Major Assemblies with applicable description model and year usage Service notes are provided to guide proper location ol service parts Parts used in conjunction with Major Assemblies and are not listed as details are located in the appropriate text group Hang on or loose items T O L O Ci AT EE P A R I iii Major Assemblies must be known Please refer to major assembly identification aids vehicle serial number plate truck broadcast sheet service parts identification label major component part number label Mlajor Assembly plarts book group Major Assembly details are listed alphabetically in a vertical chart form by line number Each line has one description only and includes GMT and WDDGM group numbers for reference General Motors uses two different grouping systems for l ruck parts books The GMT system is used for all heavy duty modlel parts books and the r lfjX DGM system for the medium duty model books Please refer to the General Inlformatibn Pages for detailed parts group usage information IF NOUN NAME IS NOT KNOWN Refer to the Illustration Catalog keeping in mind th e t lajor Group number and described area Locate the appropriate illustration and determine llhe part required on the illustration The noun name and group nulmber is listed in the legend Please refer to the Il ustration Catalog ntroduction pages for adlditional user information IF NOUN NAME IS KNOWN Refer to the AIphabetical Index as a guide to identify group numb er Please note If the group number is not found in the l ext the group is charted Scan down the chart lines and locate noun name llsing group number as a guide Description and or usage is also provided to assist identification Locate the Major Assembly part number at the l op Clf the chart and scan down to line number of the parts noun name In this box you will find the quantity required part number and vendor number or note 6 1 cram