GM TH400 TECHNICAL SERVICE MANUAL VOLUME ONE covers theory of operation, individual and master hydraulic circuit diagrams (including variable pitch), diagnosis and testing, and includes various technical resources relative to the TH400. This is the most complete collection of information currently available. Many rare illustrations and diagrams as well as extensive technical resources make this one of a kind reference manual a must for the novice and seasoned professional. In depth explanations of all operating systems unique to the GMTH400. Over 200 pages.