For 5.7L Hemi engines (common in Dodge Ram, Charger, Challenger, Chrysler 300, etc.), obtaining the precise serpentine belt diagram is critical due to variations based on accessory drive options and Model Year Design (MYD). Using an incorrect diagram leads to belt derailment or component damage.
Critical Components & Identification
- Crank Pulley (A): Drives the entire system. Largest pulley at engine bottom.
- Automatic Belt Tensioner (B): Spring-loaded arm with smooth pulley surface. Located center/top-right.
- Power Steering Pump (C): Uses a grooved pulley. Typically on driver's side.
- Water Pump (D): Uses a grooved pulley. Located engine front, near crank.
- Air Conditioning Compressor (E): Uses a grooved pulley. Position varies (often passenger side).
- Alternator (F): Uses a grooved pulley. Usually opposite power steering pump.
- MDS Solenoid Pulley (K) (if equipped): Smooth idler pulley specific to MDS engines. Crucial to routing accuracy.
- Fixed Idler Pulleys (Smooth): Often labeled numerically (e.g., "1", "2"). Route belt non-driven side.
Accessing The Correct Diagram
Locate the Engine Decal:
Most 5.7L Hemi engines feature a dedicated belt routing decal affixed to the radiator fan shroud, underside of the hood, or engine cover. Prioritize this decal for your specific VIN.
Factory Service Manual (FSM) Reference:
Consult the FSM for your specific model year and vehicle configuration. Diagrams differ significantly based on:
- Presence of MDS (Multi-Displacement System)
- Air conditioning compressor type
- Underdrive pulleys (if installed)
- Ancillary component additions (e.g., supercharger)
Standard Routing Guidance (Example - Consult Your Source)
Common NON-MDS Routing (Simplified):
Crank (A) -> Water Pump (D) -> Power Steering (C) -> A/C Compressor (E) -> Tensioner Pulley (B) -> Idler Pulley(s) -> Alternator (F) -> Back to Crank (A)
Common MDS Routing (K Pulley Involved):
Crank (A) -> MDS Pulley (K) -> Power Steering (C) -> Water Pump (D) -> A/C Compressor (E) -> Tensioner Pulley (B) -> Idler Pulley -> Alternator (F) -> Back to Crank (A)
Installation Precautions
- Disable Tensioner Correctly: Use a 1/2" drive breaker bar/socket ONLY on the tensioner arm square. Never pry on the pulley or surrounding components.
- Grooved Pulleys Only: Ensure belt ribs engage ONLY with grooved pulleys (Crank, Water Pump, P/S, A/C, Alternator). Smooth pulleys contact the belt's flat backside.
- Confirm Full Seating: After routing and releasing tensioner, manually rotate the crank 2+ full rotations clockwise (using crank bolt) to ensure the belt seats correctly in ALL pulley grooves before starting the engine.
Misrouting causes immediate failure. ALWAYS verify routing against your vehicle's specific decal or FSM diagram.