105931-9610 ZEXEL 9 420 612 697 BOSCH GOVERNOR 9420612697 1059319610 1157706920

Temporary corrections to the charts in this book will be printed in the publication ENGINE NEWS. Announcement for revised reprints of this book will be made in PREVIEW.These instructions are intended to acquaint you with the content of the rack setting charts. A description is given of the information to be found under each column heading. Read these instructions carefully so you can better understand the information presented.After reading and understanding these instructions, use the following suggestions to aid in the actual use of the rack setting charts.1. Determine and write down the engine model and engine serial number.2. Locate the correct rack setting chart.3. Locate the correct segment of the chart being used. Particular attention must be focused on the model and serial number.4. Read all notes pertaining to the engine being repaired. The notes are just as important as any other information that is presented on the rack setting chart.Column Headings
Column headings and arrangement of material can vary from chart to chart according to data requirements for the engines. A brief description of each column heading, note and symbol follows. See Fig. 1.Model
The MODEL column lists the description of the engine, and the serial number range to which the data applies. Be sure to use the data from the correct serial number range for the engine being repaired.Engine Full Load RPM
The column lists the engine speed (under load) at which the rack is positioned to permit maximum allowable amount of fuel to the engine per unit of time. Turbocharger speed, inlet manifold pressure and horsepower output are at their maximum for the listed rack setting. A tolerance of 10 RPM is allowed.Engine High Idle RPM
This column lists the high idle speed of the bare engine when driving a dynamometer. Use the figures in the chart when adjusting high idle in the truck. A tolerance of 30 RPM is allowed in most applications.Brake Horsepower
This column lists the power available at the flywheel, without fan, and within the limitations indicated in the charts. A tolerance of 3% of this value is normal from a new or reconditioned engine.
Fig. 1Rack Setting
The rack setting is the distance the rack must travel from the centered (sometimes referred to as zero) position, to supply sufficient fuel, to produce the expected power output of the engine. Rack setting is controlled by a stop bar or torque spring that is located within the governor. The stop bar and/or torque spring limits the maximum travel of the fuel rack. Rack setting procedure is explained and illustrated in the TESTING AND ADJUSTING Section of the applicable service manual.All rack settings are plus (+) settings unless otherwise indicated with a minus (-) sign. See Fig. 2.Torque Spring And Spacer
This column lists the part number and thickness of the torque spring, and only those spacers or shims installed between the torque spring and stop. Any shims located behind the stop are not listed. The dimensions are in inches and are for means of identification.
Fig.