2019 Nissan Frontier Serpentine Belt Routing, Length & Part Numbers

As an ASE-certified master technician, I’ve replaced countless drive belts on the Nissan Frontier. The 2019 Nissan Frontier is a dependable midsize truck, primarily equipped with the workhorse 4.0L VQ40DE V6 engine (though a 2.5L 4-cylinder is also available on base models). This guide focuses on the 4.0L V6, providing you with everything you need to know about its serpentine belt, including routing, part numbers, and replacement tips.

Quick Answer: Part Numbers and Specs (4.0L V6)

Before you begin, make sure you have the correct parts for your 2019 Nissan Frontier 4.0L V6. Always double-check fitment if you have the 2.5L engine, as the parts differ.

• Rib Count: 7-rib design
• Belt Length: Approximately 84.1 inches
• OEM Belt Part Number: Nissan 11920-EA20A
• Aftermarket Cross-References: Gates K070841, Dayco 5070840, Continental 4070840
• Auto-Tensioner Part Number: Nissan 11955-EA20B (or Gates 38385)
• Idler Pulley Part Number: Nissan 11925-EA00A (or Gates 36173)

Belt Routing

Since we cannot render an image of the routing path here, it is highly recommended that you take a clear photograph of your existing belt before you remove it. The 4.0L V6 serpentine belt drives all the major accessories in a single, continuous loop.

Follow this text-based step-by-step routing description when installing your new belt:

1. Start by looping the belt around the bottom of the Crankshaft Pulley (the largest pulley at the bottom center).
2. Route the belt up the passenger side, over the A/C Compressor.
3. From the A/C compressor, run it up and around the Auto-Tensioner pulley.
4. Bring it up and over the top-center Idler Pulley.
5. Route it down and around the driver-side Alternator.
6. Bring it down to the lower driver-side Power Steering Pump.
7. Finally, loop it up and over the smooth Water Pump / Fan Pulley in the center, returning down to the Crankshaft Pulley.

Ensure the ribbed side of the belt rides against all grooved pulleys (Crankshaft, Alternator, Power Steering, A/C) and the flat side rides against the smooth pulleys (Tensioner, Idler, Water Pump).

How to Replace the Serpentine Belt

Replacing the belt on a 2019 Frontier 4.0L is a straightforward process that can usually be done in under 30 minutes.

1. Prepare the Tool: Locate the auto-tensioner on the passenger side of the engine block. It features a square 3/8-inch drive hole in the tensioner arm.
2. Release the Tension: Insert a 3/8" drive breaker bar (or a dedicated serpentine belt tool) into the square slot on the tensioner. Rotate the tensioner counterclockwise (towards the driver’s side) to release the pressure on the belt.
3. Remove the Belt: While holding the tensioner open, slip the old belt off the easiest accessible pulley (usually the idler pulley or the alternator). Slowly release the tensioner back to its resting position.
4. Install the New Belt: Route the new belt following the steps in the section above, leaving the tensioner pulley for last.
5. Apply Tension: Turn the breaker bar counterclockwise again to compress the tensioner, slip the belt over the final pulley, and carefully let the tensioner clamp down onto the belt.
6. Verify: Double-check that the belt is perfectly seated in the grooves of all pulleys before starting the engine.

Replacement Interval

For the 2019 Nissan Frontier, the factory maintenance schedule recommends inspecting the drive belt every 10,000 miles or 12 months. However, the standard replacement interval for modern EPDM belts is between 60,000 to 90,000 miles. Even if the mileage hasn't been reached, replace the belt if it is over 7 years old, as the rubber degrades over time.

Signs of a Failing Belt or Tensioner

Don't wait for the belt to snap and leave you stranded. Look out for these common warning signs:

• Squealing or Chirping Noises: Often worse on cold startups or when turning the steering wheel lock-to-lock. This indicates belt slippage or a worn tensioner bearing.
• Visible Wear: Look for fraying edges, deep cracking, missing ribs, or a shiny, glazed appearance on the belt surface.
• Accessory Malfunctions: A slipping belt might cause the power steering to feel heavy, the A/C to blow warm, or the battery warning light to flicker.
• Tensioner Bounce: While the engine is idling, look at the tensioner arm. If it is bouncing erratically, the internal spring is weak and the tensioner assembly must be replaced alongside the belt.

If you don't feel comfortable tackling this job yourself, don't worry. Find a trusted shop on Repairius.