Serpentine Belt

Replace the serpentine belt on a 2008 Dodge Viper 8.4L V10, including inspection of tensioner and idler pulleys.

Warnings

Tools required

Parts

• Serpentine belt × 1 — Mopar 05083694AA or equivalent 6-rib belt

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 hood prop.
4. Photograph or sketch the serpentine belt routing path for reference during reinstallation.

Procedure

1. 1

   Locate and inspect belt routing
   The serpentine belt routing diagram is typically located on a decal on the radiator core support or hood underside. Verify the diagram matches the current belt path. The belt routes around the crankshaft pulley, water pump, power steering pump, alternator, A/C compressor, and idler pulleys with the tensioner maintaining proper tension. Note the position of the tensioner pulley in the center-left area of the accessory drive system when viewed from the front of the vehicle.
2. 2

   Access the belt tensioner
   The automatic belt tensioner is located on the left side of the engine block when viewed from the front. It uses a spring-loaded arm with a pulley to maintain belt tension. Identify the drive fitting in the tensioner arm casting (commonly a 1/2" square drive or a hex fitting), which accepts a breaker bar or large ratchet to rotate the tensioner and release belt tension. Confirm the exact fitting size before selecting a tool.
3. 3

   Release belt tension and remove belt
   Insert the appropriate tool (breaker bar with correct drive size) into the tensioner arm fitting. Rotate the tensioner in the direction that swings the pulley away from the belt to release tension (confirm direction by observing tensioner arm movement). This requires significant force due to the spring pressure. This requires significant force due to the spring pressure. While holding the tensioner rotated, slip the belt off the alternator pulley or another easily accessible pulley. Carefully release the tensioner back to its resting position. Remove the belt from all remaining pulleys, noting any obstructions or tight clearances for reinstallation.
4. 4

   Inspect tensioner and idler pulleys
   With the belt removed, manually spin each idler pulley and the tensioner pulley. Each should rotate smoothly without roughness, grinding, or excessive noise. Check for side-to-side play in each pulley bearing. Inspect the tensioner arm travel by rotating it through its full range of motion—it should move smoothly with consistent spring resistance and return to the stop position when released. Look for oil leakage from the tensioner damper mechanism. Replace any pulley or the tensioner assembly if wear or damage is detected.
5. 5

   Inspect old belt for wear patterns
   Examine the removed belt for glazing on the rib surfaces, cracks in the rib valleys, chunking of the rib material, or uneven wear patterns. Edge wear or fraying indicates pulley misalignment. Oil contamination appears as a shiny, darkened surface. These wear patterns help diagnose accessory drive problems that should be corrected before installing the new belt.
6. 6

   Route new serpentine belt
   Using your photo or the routing diagram, install the new belt around all pulleys except the tensioner pulley or one other easily accessible pulley. Typical routing starts at the crankshaft, then proceeds to the water pump, power steering pump, alternator, A/C compressor, and idler pulleys. Ensure the belt ribs properly seat in each pulley groove—the flat back of the belt contacts smooth pulleys while the ribbed side engages grooved pulleys. Verify the belt is not twisted anywhere in the routing path.
7. 7

   Apply tensioner and seat belt
   Insert your breaker bar or ratchet into the tensioner arm fitting and rotate the tensioner in the direction that swings the pulley away from the belt to create slack (same direction used to release tension during removal). Route the belt over the tensioner pulley (or the pulley you left for last), ensuring proper rib engagement. Carefully release the tensioner to apply tension to the belt. Remove the tool from the tensioner fitting. Walk around the belt path and visually verify the belt is properly seated in the center of each pulley with all ribs fully engaged.
8. 8

   Verify belt alignment and tension
   Inspect each pulley to confirm the belt runs centered without tracking toward either edge. The automatic tensioner should position its pulley arm within the normal operating range indicator marks (if visible on the tensioner body). The belt should have firm tension with minimal deflection when pressed between pulleys. No adjustment is required on the automatic tensioner system—if tension appears incorrect, inspect for wrong belt length or tensioner failure.

Reassembly

1. No disassembly of other components was required for this procedure.

Verification

• Start the engine and verify smooth belt operation with no squealing, chirping, or slapping noises.
• Observe the belt path while the engine runs to confirm proper tracking and no movement toward pulley edges.
• Turn the steering wheel lock-to-lock and activate the A/C system to load accessories and verify belt remains properly tensioned without slipping.
• Shut off engine and perform a final visual inspection of belt seating on all pulleys.

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