Original 1981 GMC Truck Dealer Unit Repair Manual. This Manual covers the Light Truck Models [including Sierra, Jimmy, Suburban, Van, Rally and STX Models]. These are what the Dealerships used to service and repair your truck. It has information, illustrations, diagrams, specifications and procedures to repair the components of your Light Duty Truck. It does not cover the removal and installation of these components, which was covered in a separate Service Manual that is not included. Very useful and informative tool for the GMC Owner which was not available to the public. Good condition with normal wear and soiling from use in a Dealership [see photos].