Serpentine Belt Tensioner

This procedure covers the removal and replacement of the serpentine belt tensioner on the 2011-2014 Ford F-150 with the 5.0L Coyote V8 engine, including belt removal and reinstallation.

Warnings

Tools required

Parts

• Serpentine belt tensioner assembly × 1 — Use OEM Motorcraft specification
• Serpentine belt (if worn or cracked) × 1 — Use OEM specification for 5.0L Coyote

Preparation

1. Ensure engine is completely cool to the touch
2. Position vehicle on level ground and engage parking brake
3. Photograph or diagram the serpentine belt routing from multiple angles
4. Verify replacement tensioner matches existing unit before beginning removal
5. Gather all tools within reach to minimize time spent with belt removed

Procedure

1. 1

   Access the serpentine belt
   Open hood and locate the serpentine belt at the front of the engine. The belt tensioner is located on the passenger side of the engine block, below the alternator. Ensure you have clear visual access to the tensioner pulley and mounting bolt.
2. 2

   Release belt tension
   Insert a 3/8 inch drive breaker bar into the square hole on the tensioner arm. Rotate the tensioner clockwise (toward the passenger side) to relieve tension on the belt. The tensioner will move approximately 45-60 degrees. Maintain controlled pressure throughout the movement.
   ⚠Keep fingers clear of pulleys and belt while rotating the tensioner. Sudden slippage can cause injury.
3. 3

   Remove serpentine belt
   While holding tension on the breaker bar, slip the serpentine belt off the alternator pulley (easiest access point). Slowly release tension on the breaker bar, allowing the tensioner to return to its resting position. Remove the belt completely from all pulleys, noting its condition for potential replacement.
4. 4

   Remove tensioner mounting bolt
   Using the appropriate metric socket (typically 15mm), remove the single bolt securing the tensioner to the engine block. The bolt threads into the engine block and may require moderate force to break free. Support the tensioner with your other hand as you remove the bolt completely.
   Torque spec

   Belt Tensioner Bolt24 Nm (18 lb-ft)
5. 5

   Remove tensioner assembly
   Pull the tensioner assembly straight out from the engine block. The tensioner may have a locating pin or alignment feature that requires slight wiggling to disengage. Inspect the mounting surface on the engine block for debris or damage.
6. 6

   Inspect and prepare new tensioner
   Examine the old tensioner for bearing noise, excessive play in the pulley, or fluid leakage. Verify the new tensioner matches the mounting configuration and pulley size. Check that the tensioner arm moves smoothly through its full range of motion and returns to the resting position under spring tension.
7. 7

   Install new tensioner
   Align the new tensioner with the mounting hole on the engine block, ensuring any locating pins are properly seated. Insert the tensioner mounting bolt by hand and thread it in several turns to ensure proper engagement. Do not fully tighten yet.
   Torque spec

   Belt Tensioner Bolt24 Nm (18 lb-ft)
8. 8

   Torque tensioner bolt
   Using a torque wrench, tighten the tensioner mounting bolt to 55.0 Nm (41.0 lb-ft). Apply torque in a smooth, steady motion. Verify the tensioner is seated flush against the engine block and does not rotate during tightening.
   ⚠Proper torque is critical for tensioner function and safety. Under-torquing can allow the tensioner to shift during operation, while over-torquing may damage the engine block threads.
   Torque spec

   Belt Tensioner Bolt24 Nm (18 lb-ft)
9. 9

   Route new serpentine belt
   Following your routing diagram or photo, thread the serpentine belt around all pulleys EXCEPT the alternator pulley. Ensure the ribbed side of the belt contacts all grooved pulleys. Double-check routing against your reference before proceeding. The belt should wrap: crankshaft, power steering pump, A/C compressor, idler pulley, water pump, and tensioner pulley.
10. 10

    Install belt on alternator
    Insert the breaker bar into the tensioner and rotate clockwise to create slack. Route the belt over the alternator pulley, ensuring it is centered in the pulley grooves. Slowly release the breaker bar, allowing the tensioner to apply proper tension to the belt. Remove the breaker bar.
11. 11

    Verify belt installation
    Visually inspect all pulleys to confirm the belt is properly seated in all grooves with no twists or misalignment. The belt should run straight and centered on each pulley. Manually rotate the crankshaft one full revolution clockwise (using a socket on the crankshaft bolt) to verify smooth operation and proper tracking.

Reassembly

1. No additional reassembly required beyond the procedure steps above

Verification

• Start the engine and observe belt operation for the first 30 seconds, listening for squealing or unusual noises
• Verify the belt tracks centered on all pulleys without slipping or wandering side-to-side
• Check that the tensioner pulley rotates freely without wobble or bearing noise
• Confirm proper tension by pressing on the belt between pulleys - it should deflect approximately 1/2 inch with firm thumb pressure
• Re-check tensioner mounting bolt torque after test run if desired for verification

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