How to Replace the Drive Belt on a 2003 Altima
- 1). Open the hood of your 2003 Nissan Altima and locate the belt routing diagram on the top passenger's side of the radiator fan cover. This diagram outlines the exact routing of the belt around each pulley. Refer to this diagram when routing the new belt around the pulleys.
- 2). Locate the automatic belt tensioner on the front of the engine directly below the water pump pulley. The belt tensioner has a roller pulley on one end that is attached to the tensioner arm by a bolt. Use the bolt head to turn the tensioner.
- 3). Pivot the tensioner by the bolt head counterclockwise with a breaker bar and a socket. Pull the belt off of the roller pulley and release the tensioner.
- 4). Slide the belt out of each accessory pulley then out of the engine bay. Match the old belt to the new belt to ensure that the new belt is the proper size.
- 5). Route the new belt around all of the accessory pulleys by referring to the belt routing diagram. Start with the pulley attached to the crankshaft and leave the roller pulley attached to the tensioner for last.
- 6). Pivot the tensioner by the bolt head counterclockwise and slide the new belt around the roller pulley. Release the tensioner. Inspect the belt to make sure it is centered under the roller pulley and is seated inside of each accessory pulley.
- 7). Crank the engine of your 2003 Nissan Altima and let the motor run for 10 seconds to completely seat the new belt inside of the pulleys. Turn the engine off and close the hood.
Source...