Heavy duty belt kits built for high-demand environments.
Designed for commercial, fleet, and work vehicles, our heavy duty engine components are made to withstand extreme mileage, heavy loads, and challenging conditions.
For when uptime matters, and performance can’t fail.
Heavy Duty Accessory Drive Kits
Help your engine tackle high-stress work environments.
Heavy Duty Accessory Drive Components
Reinforced belts, rugged tensioners, and durable pulleys.
Keep your engine turning mile after mile.
Cloyes delivers solutions that keep heavy duty engines turning in commercial conditions. Reinforced construction and triple-sealed bearings help control vibration and wear in the toughest settings.
Hassle-Free Installation
Each heavy duty accessory drive kit offers frustration-free installation.
Stronger Materials
The construction of our components helps extend your engine’s life.
OE-Quality
The fit, form, and finish are meant for precise alignment.
The knowledge behind the repair.
Explore technical resources, installation guidance, and product videos developed to help technicians approach heavy duty engine repairs with confidence.
Tech Video
Tech Video
Tech Byte: What Else to Service When Changing Your Timing Chain
See what else to inspect or service during a timing chain replacement, including accessory drive, water pump, and VVT components already exposed during repair.
tech-byte-what-else-to-service-when-changing-your-timing-chain
September 29, 2026
Tech Video
Tech Video
Tech Byte: Why Do Timing Chains Need Replacing
Learn why timing chains wear and elongate over time, how that affects camshaft-to-crankshaft timing, and why timing-system service becomes necessary.
tech-byte-why-do-timing-chains-need-replacing
September 29, 2026
Tech Video
Tech Video
GM 3.0L/3.6L HFV6 Timing Chain Kit | Cloyes 9-0753S Unboxing
Take a closer look at the Cloyes 9-0753S Timing Chain Kit for GM 3.0L and 3.6L HFV6 engines.
gm-3-0l-3-6l-hfv6-timing-chain-kit-cloyes-9-0753s-unboxing
September 9, 2026
Tech Center
Looking for a specific heavy duty accessory drive part?
Use the links below to search our part finder or see where Cloyes products are sold near you.
Heavy Duty FAQ’s
Find answers to common questions we receive about our heavy duty accessory drive kits and components.
Contact UsWhat Heavy Duty products does Cloyes offer?
Cloyes offers timing and front-end accessory drive products for medium- and heavy-duty vehicle applications. The portfolio includes application-specific timing products, serpentine belt kits and individual accessory drive components such as belts, tensioners and pulleys. Available coverage can be found through the Cloyes Part Finder.
What types of vehicles use Cloyes Heavy Duty products?
Cloyes Heavy Duty products are designed for commercial, fleet and work-vehicle applications. Coverage varies by vehicle and engine, so use the Cloyes Part Finder to confirm the correct timing or accessory drive product for the application being serviced.
How are Heavy Duty timing products different from passenger-vehicle timing products?
Heavy Duty timing products are designed around the fit, operating requirements and service demands of the specific commercial engine application. Because configurations and repair requirements vary by engine, technicians should confirm the correct components and installation instructions by application rather than selecting parts based on appearance or dimensions.
Does Cloyes offer complete Heavy Duty accessory drive kits?
Yes. Cloyes offers application-specific Heavy Duty serpentine belt kits that bring the primary accessory drive wear components together in one package. Depending on the application, a kit may include a fabric-backed EPDM belt, tensioner, pulleys and a belt-routing guide. Check the catalog listing to confirm the exact contents of each kit.
Are Heavy Duty belts, tensioners and pulleys available individually?
Yes. Cloyes offers individual Heavy Duty accessory drive components for applications that do not require a complete system replacement. The entire drive system should still be inspected because belt condition, pulley alignment, bearing wear and tensioner performance can affect one another.
Why should the complete Heavy Duty accessory drive system be inspected?
Commercial and work vehicles may experience high mileage, extended operating hours, frequent load changes and demanding driving conditions. Inspecting the belt, tensioner and pulleys together helps identify related wear that could affect belt tension, alignment and system operation.
How do I choose between a Heavy Duty and High Performance timing product?
Choose the product based on its cataloged application and the engine’s intended use. Cloyes Heavy Duty timing products are developed for medium- and heavy-duty vehicle applications. Cloyes High Performance timing products are intended for racing and modified engine builds, including specialized competition vehicles. A performance product described as “heavy duty” is not automatically intended for a commercial Heavy Duty application.
How do I find the correct Cloyes Heavy Duty product?
Use the Cloyes Part Finder and enter the complete vehicle and engine information. Heavy Duty timing and accessory drive components are application-specific, so always verify the part number, included components and installation requirements before beginning the repair.
