2022 Mercedes-Benz Metris Serpentine Belt Routing & Part Numbers

Quick Answer

• Belt Length: Approximately 2210mm (87 inches)
• Rib Count: 6-rib
• OEM Belt Part Number: A0029933596 (Please verify with your VIN)
• Aftermarket Cross-Reference (Confirm with supplier):
  • Gates K060870
  • Dayco 5060870
  • Continental Elite 4060870
• Auto-Tensioner Part Number: A2702000670 (Please verify with your VIN)
• Idler Pulley Part Number: A2702020219 (Please verify with your VIN)

Belt Routing

The serpentine belt on your 2022 Mercedes-Benz Metris powers essential accessories like the alternator, power steering pump, and air conditioning compressor. Before you begin any work, take a clear photograph of the existing belt routing! This will be your most valuable reference during reinstallation.

The routing for the 2022 Mercedes-Benz Metris 2.0L (M274) engine typically follows this path:

1. Starting from the crankshaft pulley (the lowest main pulley, usually the largest),
2. The belt travels upward to the A/C compressor pulley,
3. From the A/C compressor, the belt goes to the idler pulley (a smooth, non-driven pulley used for routing and tension),
4. From the idler pulley, it goes to the alternator pulley (usually high up on the engine, charging the battery),
5. Next, it wraps around the power steering pump pulley,
6. Then to the water pump pulley,
7. Finally, it passes around the automatic belt tensioner pulley before returning to the crankshaft pulley.

Always double-check the routing against the diagram under your hood or the photograph you took. Different engine options or accessory configurations may have slightly different paths.

How to Replace the Serpentine Belt

Replacing the serpentine belt on your Mercedes-Benz Metris requires proper tools and careful attention. The primary tool you'll need is a serpentine belt tool or a long 3/8" drive breaker bar. This will allow you to release the tension on the automatic belt tensioner.

1. Safety First: Ensure the engine is off and cool. Disconnect the negative terminal of the battery.
2. Locate the Tensioner: Identify the automatic belt tensioner. It will have a square slot (usually 3/8" or 1/2") for your tool.
3. Relieve Tension: Insert your serpentine belt tool or breaker bar into the tensioner's square slot. Rotate it clockwise (or counter-clockwise, depending on the tensioner design – observe which way releases tension) to relieve the tension on the belt.
4. Remove the Belt: While holding tension, slip the belt off one of the pulleys (often easiest from a smooth idler pulley).
5. Inspect Pulleys: With the belt off, spin each pulley by hand. Listen for noises, and feel for any roughness or excessive play. Replace any faulty pulleys.
6. Route the New Belt: Following your diagram or photograph, carefully route the new belt around all the pulleys, leaving the tensioner pulley or an easily accessible smooth pulley for last.
7. Tension the New Belt: Again, use your tool to relieve tension on the tensioner, slip the new belt onto the remaining pulley, and slowly release the tensioner. Ensure the belt is properly seated in all pulley grooves.
8. Double-Check: Visually inspect the entire belt path to ensure it's correctly routed and fully seated in all grooves.
9. Reconnect Battery: Reconnect the negative battery terminal. Start the engine briefly and listen for any unusual noises. Turn off and inspect the belt again after the first run.

Replacement Interval

Mercedes-Benz generally recommends inspecting the serpentine belt at regular service intervals (typically every 20,000 to 30,000 miles or every 2 years). Replacement is usually recommended around 60,000 to 100,000 miles, or if signs of wear are observed during inspection, whichever comes first. Always refer to your vehicle's owner's manual for the most accurate and up-to-date maintenance schedule, as driving conditions and climate can affect these recommendations.

Signs of a Failing Belt or Tensioner

Don't wait for a complete belt failure, as this can leave you stranded and potentially damage other components. Be aware of these warning signs:

• Squealing or Chirping Noises: This is one of the most common signs of a worn or misaligned belt, or a failing tensioner/pulley. The noise may be more prominent during cold starts or when turning the steering wheel.
• Cracks, Fraying, or Glazing: Visually inspect the belt. Cracks on the ribbed side, fraying along the edges, or a smooth, shiny (glazed) appearance are all indicators of wear and reduce the belt's ability to grip pulleys.
• Loss of Power Steering, A/C, or Charging: If the belt slips or breaks, you'll immediately notice a loss of function for the accessories it drives. The battery light may come on if the alternator isn't spinning.
• Vibration of the Tensioner: A tensioner that is vibrating excessively or making knocking noises indicates internal wear and potential failure. The belt may also appear to "flap" or oscillate excessively.
• Misalignment: Observe if the belt appears to be riding improperly on any pulley, indicating a bent pulley or a failing bearing.

If you notice any of these symptoms, it's crucial to inspect your serpentine belt system promptly. A failing belt can lead to a breakdown, and a failing tensioner can cause premature belt wear or an outright belt failure.

Find a trusted shop on Repairius.