Remove and replace the serpentine belt that drives the alternator on the 6.7L Cummins diesel engine.

Warnings

Tools required

Parts

• Serpentine belt × 1 — Use OEM specification or Gates K060965

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine to cool completely if recently operated
3. Photograph or diagram the belt routing path before removal for reference
4. Open hood and secure with prop rod

Procedure

1. 1

   Locate belt tensioner
   Identify the automatic belt tensioner on the driver's side of the engine. The tensioner is spring-loaded and maintains proper belt tension automatically. Note the direction of tensioner rotation needed to relieve belt tension.
2. 2

   Relieve belt tension
   Insert a 3/8" ratchet or breaker bar into the square 3/8" drive hole on the tensioner arm. Rotate the tensioner clockwise (toward the front of the vehicle) to relieve tension on the belt. The tensioner will move approximately 2-3 inches.
3. 3

   Remove old belt
   While holding tension released, slip the belt off the alternator pulley first, then carefully release the tensioner. Once tension is released, remove the belt from all remaining pulleys including the crankshaft, water pump, idler pulley, and power steering pump. Remove belt from engine compartment.
4. 4

   Inspect pulleys and tensioner
   With belt removed, inspect all pulleys for damage, wobble, or rough rotation. Check tensioner for smooth operation and proper spring return. Spin each pulley by hand to verify bearings are not rough or seized. Replace any damaged components before installing new belt.
5. 5

   Route new belt
   Following your belt routing diagram or photo, route the new belt around all pulleys EXCEPT the alternator pulley. Typical routing: crankshaft (bottom center), water pump, idler pulley, power steering pump, then prepare to loop over alternator. Ensure belt is properly seated in each pulley groove with ribs aligned.
6. 6

   Install belt on alternator
   Using the 3/8" ratchet or breaker bar, rotate the tensioner clockwise again to create slack. Route the belt over the alternator pulley, ensuring it is fully seated in the pulley grooves. Carefully release the tensioner to apply proper tension to the belt.
7. 7

   Verify belt alignment
   Visually inspect that the belt is properly seated on all pulleys with the ribs fully engaged in each groove. The belt should track centered on all pulleys without riding on edges. Verify the belt is not twisted at any point in the routing path.

Reassembly

1. Double-check that belt is properly routed according to diagram and seated on all pulleys
2. No torque specifications apply for this belt replacement procedure

Verification

• Start the engine and observe belt operation for 30 seconds, checking for proper tracking and no slipping or squealing
• Verify alternator is charging by checking battery voltage (should read 13.5-14.5 volts with engine running)
• Listen for any unusual noises from belt or pulleys during operation
• Shut off engine and recheck belt tension and alignment after initial run

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