2023 Kenworth T680 Serpentine Belt: Routing & Replacement Guide

Quick answer

• Belt Length: Varies by engine – Most common engines (e.g., PACCAR MX-13) typically use a belt around 106-108 inches.
• Rib Count: 8-rib
• OEM Belt PN: Varies by engine configuration. For PACCAR MX-13, common OEM PNs include 1937666PACCAR. Always verify with your VIN.
• Aftermarket Cross-references (PACCAR MX-13 common):
  • Gates K081075RPM (or similar, verify length)
  • Dayco 5081075 (or similar, verify length)
  • Continental Elite 4081075 (or similar, verify length)
• Auto-Tensioner PN: Varies by engine. For PACCAR MX-13, a common PN is 1937651PACCAR. Always verify with your VIN.
• Idler Pulley PN: Varies by engine. For PACCAR MX-13, common PNs include 1937652PACCAR. Always verify with your VIN.

Belt routing

The 2023 Kenworth T680, particularly with the prevalent PACCAR MX-13 engine, utilizes an 8-rib serpentine belt to drive essential accessories. Before attempting any belt removal, it is crucial to take a clear photograph of your existing belt's routing diagram. This will serve as an invaluable reference during reinstallation.

Here's a general step-by-step description of the routing path for a common PACCAR MX-13 configuration. Please note that minor variations can exist based on specific engine options and accessory layouts.

1. Crankshaft Pulley: The journey begins at the largest pulley, the crankshaft pulley, which powers all other accessories. The belt typically wraps around the bottom of this pulley.
2. A/C Compressor: From the crankshaft, the belt often travels upwards to the air conditioning (A/C) compressor pulley, usually located on the lower passenger side of the engine. It will typically wrap around the top or side of this pulley.
3. Idler Pulley (Lower/Middle): After the A/C compressor, the belt may encounter an idler pulley, which helps guide the belt and maintain proper tension. This idler could be positioned in a lower or middle section of the belt path, wrapping around its smooth surface.
4. Alternator: The belt then proceeds to the alternator pulley, usually located higher up on the engine, often on the driver's side. It commonly wraps around the top or side of the alternator pulley.
5. Power Steering Pump: Following the alternator, the belt will engage the power steering pump pulley, usually found in a similar height range or slightly lower. The belt typically runs over the top or side of this pulley.
6. Water Pump: Next, the belt typically drives the water pump pulley, essential for engine cooling. This pulley is often centrally located on the front of the engine, and the belt wraps around a portion of it.
7. Idler Pulley (Upper/Middle): Depending on the engine configuration, another idler pulley might be present to further guide the belt before it reaches the tensioner. This idler would also have the belt running over its smooth surface.
8. Automatic Belt Tensioner: Finally, the belt reaches the automatic belt tensioner. This component applies constant tension to the belt. The belt generally wraps around the tensioner pulley's smooth surface before returning to the crankshaft pulley, completing the loop.

How to replace the serpentine belt

Replacing the serpentine belt on a 2023 Kenworth T680 requires basic mechanical understanding and the right tools. Ensure the engine is off and cool before starting.

1. Gather Tools: You will need a serpentine belt removal tool or a 3/8-inch breaker bar (or a wrench of appropriate size for the tensioner arm, if applicable) to release tension.
2. Document Routing: Crucially, take a clear photo of the existing belt's routing before removal. Refer to the