This procedure covers the inspection, removal, and replacement of the alternator drive belt (serpentine belt) on the 2019-2024 Toyota RAV4 with the 2.5L I4 gasoline engine.

Warnings

Tools required

Parts

• Alternator drive belt (serpentine belt) × 1 — Use OEM specification - Toyota part number varies by production date

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine to cool completely if recently operated
3. Open hood and secure with prop rod
4. Photograph the serpentine belt routing pattern from multiple angles for reference
5. Inspect the belt tensioner and idler pulleys for noise, resistance, or play while belt is still installed

Procedure

1. 1

   Locate belt tensioner and routing
   Identify the automatic belt tensioner assembly on the front right side of the engine block. Verify the belt routing pattern matches your reference photos or the underhood diagram. The belt routes around the crankshaft pulley, alternator, water pump, and A/C compressor with the tensioner pulley applying spring pressure.
2. 2

   Inspect belt condition before removal
   Check the belt for cracks, glazing, fraying, or missing ribs. Measure belt wear if a gauge is available. Note any contamination from oil or coolant which indicates other system leaks requiring attention.
3. 3

   Relieve belt tension
   Using a 14mm socket and ratchet, rotate the belt tensioner clockwise (toward the front of the vehicle) to compress the spring and relieve tension on the belt. The tensioner pulley will move and create slack in the belt. Maintain steady pressure on the tensioner throughout belt removal.
   ⚠Do not allow the tensioner to snap back suddenly. Control the release to prevent damage to the tensioner mechanism or injury.
4. 4

   Remove belt from pulleys
   While holding the tensioner in the relaxed position, slip the belt off the alternator pulley first, then off the remaining pulleys. Once clear of all pulleys, carefully release tension on the tensioner and allow it to return to its resting position. Remove the belt from the engine bay.
5. 5

   Inspect pulleys and tensioner
   With the belt removed, manually spin each pulley (alternator, idler, tensioner, water pump) to check for roughness, binding, or excessive play. Check the tensioner for smooth operation through its range of motion. Replace any components showing wear or damage.
6. 6

   Route new belt
   Begin installing the new belt by routing it around all pulleys EXCEPT the alternator pulley, following your reference photos or routing diagram exactly. Ensure the ribbed side of the belt contacts all grooved pulleys properly. The belt should follow: crankshaft (bottom), then around A/C compressor, water pump, and tensioner pulley.
7. 7

   Install belt on alternator pulley
   Using the 14mm socket, rotate the belt tensioner clockwise again to create slack. Route the belt over the alternator pulley last, ensuring proper seating in all pulley grooves. Verify the belt is properly seated on all pulleys before releasing tension.
   ⚠Double-check belt routing before releasing tensioner. Incorrect routing can cause belt failure or component damage.
8. 8

   Release tensioner and verify installation
   Slowly and carefully release the belt tensioner, allowing it to apply proper spring tension to the new belt. Visually verify the belt is centered on all pulleys and fully seated in all grooves. The tensioner arm position should be within the normal operating range indicator marks if visible on your tensioner.
9. 9

   Rotate engine by hand
   Using a socket on the crankshaft pulley bolt, manually rotate the engine two complete revolutions clockwise (normal direction). Watch the belt throughout rotation to ensure it tracks properly on all pulleys and does not slip or misalign. Recheck belt seating on all pulleys after rotation.

Reassembly

1. No disassembly was required beyond belt removal
2. Ensure all tools are removed from engine bay before closing hood
3. Remove any rags or materials from engine compartment

Verification

• Start the engine and listen for abnormal belt noise such as squealing or chirping
• Observe the belt while engine is running at idle to confirm proper tracking and no slippage
• Turn on electrical loads (headlights, A/C, radio) to verify alternator is charging properly with the new belt under load
• After initial test drive, recheck belt seating and tension visually while engine is off and cool
• Check for proper alternator charging voltage (typically 13.5-14.5V) with a multimeter at battery terminals while engine is running

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