2013 Nissan Altima Belt Diagram for Accessories and Power Steering

This diagram applies to the 2013 Nissan Altima with the QR25DE 2.5L 4-cylinder engine, equipped with air conditioning.

Serpentine Belt Routing Path

The serpentine belt drives the alternator, power steering pump, and air conditioning compressor via the following path:

• Crankshaft Pulley (Bottom)
• Air Conditioning Compressor Pulley (A/C)
• Idler Pulley (Upper Left)
• Power Steering Pump Pulley (PS)
• Alternator Pulley (ALT)
• Automatic Tensioner Pulley
• Back to Crankshaft Pulley

Key Components

• Crankshaft Pulley: Largest bottom pulley.
• Automatic Tensioner: Spring-loaded pulley (upper right). Apply force clockwise to release tension.
• Idler Pulley: Smooth pulley providing routing guidance (upper left of A/C compressor).
• Power Steering Pump Pulley: Drivers side, below idler.
• Alternator Pulley: Passenger side, below tensioner.
• A/C Compressor Pulley: Passenger side, above crankshaft.

Replacement Procedure

1. Disable Electrical System: Turn ignition OFF, disconnect negative battery cable.
2. Locate Tensioner: Identify the automatic tensioner pulley assembly.
3. Release Tension: Insert a 3/8" drive breaker bar or socket wrench into the tensioner's square drive. Rotate the tensioner clockwise firmly until the belt becomes slack.
4. Remove Belt: Slip the belt off one of the easily accessible pulleys (often the alternator). Carefully remove the entire belt.
5. Note Routing (Critical): Verify routing against the diagram above or the underhood sticker (if present) BEFORE removing the old belt completely.
6. Install New Belt: Route the new belt over all pulleys except the tensioner pulley last. Ensure it sits correctly in all grooves.
7. Apply Tension: Rotate the tensioner clockwise again and slip the belt onto the tensioner pulley. Slowly release the tensioner to apply tension.
8. Verify Alignment: Check the belt is fully seated in all pulley grooves and routing matches the diagram exactly.
9. Reconnect Battery: Reconnect the negative battery cable.
10. Test Operation: Start the engine. Briefly operate accessories (A/C, steering). Listen for squealing or chirping noises indicating misalignment or incorrect tension.

Important Notes

• Automatic Tensioner: Never pry against the tensioner body. Use only the designated square drive.
• Idler Pulleys: While replacing the belt, spin all smooth idler pulleys by hand. Grinding or roughness indicates the pulley bearing requires replacement.
• Belt Condition: Replace if cracked, glazed, frayed, or shows significant rib wear. Inspect for fluid contamination (oil/coolant).
• V-Ribbed Belt: Ensure the new belt is the correct specification (6PK length varies slightly by specific Altima trim).
• Safety: Ensure hands, tools, and loose clothing are clear of moving components before starting the engine.