Dayco 5120738 Serpentine Belt

Dayco 5120738 Serpentine Belt Overview

The Dayco 5120738 serpentine belt is a K-section accessory drive belt built for demanding engine accessory systems. It uses EPDM with aramid reinforcement for stable operation across a wide temperature range, with 12 ribs and a straight rib profile for consistent pulley engagement.

Compatible With heavy-duty and commercial vehicle applications that call for a 12-rib K-section belt, including Cummins and CNH equipment references. This Dayco 5120738 belt is also cross-referenced to Gates K120738 for the same application.

Key Features

• EPDM construction with aramid reinforcement for durability in accessory drive service
• 12-rib, K-section design for multi-groove pulley systems
• Black belt with straight rib profile
• Effective length: 1875.03 mm / 73.82 in
• Outside circumference: 1891.03 mm / 74.45 in
• Top width: 1.66 in
• Operating temperature range: -45°F to 212°F
• Built to SAE J1459 and SAE J2432 standards

Detailed Description

Dayco 5120738 is a serpentine belt for accessory drive systems that require a 12-rib K-section profile. The EPDM rubber construction is paired with aramid reinforcement to support belt stability under heat, cold, and continuous engine operation. With its straight rib profile and standard rib depth, this belt is suited to applications where consistent pulley tracking and reliable accessory drive performance are required. Search terms such as Dayco 5120738 serpentine belt, 12 rib K-section belt, and heavy-duty accessory drive belt apply to this part.

Vehicle and equipment references associated with this part include Cummins and CNH applications, and the part number is commonly searched alongside Dayco 5120738 for replacement matching. If you are sourcing a belt for a Cummins or CNH accessory drive system, verify rib count, section, and length against the original belt before ordering.

Common Issues This Belt Can Address

• Cracking or glazing on an aging serpentine belt
• Squealing caused by belt wear or loss of grip
• Accessory drive slippage from incorrect belt length or rib wear
• Reduced alternator, water pump, or accessory drive performance from belt deterioration
• Replacement needs after inspection shows fraying, hardening, or rib damage

Installation Notes and Tips

Confirm the belt’s 12-rib K-section profile, effective length, and outside circumference against the removed belt or service information before installation. Inspect pulleys, tensioners, and idlers for wear or misalignment, since those conditions can shorten belt life. Route the belt exactly to the factory diagram and verify full rib seating across each pulley groove after installation.

Quality Assurance

This Dayco belt is manufactured to SAE J1459 and SAE J2432 standards for accessory drive belt applications. Part number 5120738 is built with EPDM and aramid reinforcement to support consistent service in demanding operating temperatures.