
Dayco Products, LLC, a division of Mark IV Industries, is a leader in research and design, manufacturing and distributing of a broad range of belts, hose, tensioners and pulleys for the automotive, trucking, construction, agricultural and industrial markets.
Recognized by both the original equipment and the automotive aftermarket as an innovative, technologically driven organization, Dayco operates a fully integrated global network of technical facilities and sales offices employing a workforce of nearly 5,000. Dayco continues to be guided by the same primary business strategy established over 100 years ago: to anticipate and satisfy the needs of our customers by providing timely, quality products and services.
The 100 Year History of Dayco
Dayco Products, LLC, a division of Mark IV Industries, is a leader in research and design, manufacturing and distributing of a broad range of belts, hose, tensioners and pulleys for the automotive, trucking, construction, agricultural and industrial markets.
Recognized by both the original equipment and the automotive aftermarket as an innovative, technologically driven organization, Dayco operates a fully integrated global network of technical facilities and sales offices employing a workforce of nearly 5,000. Dayco continues to be guided by the same primary business strategy established over 100 years ago: to anticipate and satisfy the needs of our customers by providing timely, quality products and services.
PRODUCT FAQ'S
Q. Is it true that a tensioner can be positioned properly when the locator pin is missing?
-This is incorrect. A tensioner cannot be positioned properly when the locator pin is missing, and the tensioner body covers the positioning hole.
Q. Is it true that a threaded steel positioning pin in an automatic belt tensioner can tear itself out of the aluminum housing?
-In all of our testing, we have never had a steel pin fail, pull out of the aluminum housing or damage the aluminum housing in any way.
Q. Do your steel locator pins require retrofitting on certain applications?
- Our steel locator pins are positioned in one place, accurately and require no retrofitting by installers.
Q: Is it true that Dayco’s automatic belt tensioners are universal in fit?
- Dayco does not sell any universal tensioners. Each tensioner is specifically designed to fit and function just like the OE tensioner. In fact, many of the OE tensioners we replace are Dayco tensioners that look almost identical to our replacement tensioner.
Q: Does Dayco have less coverage than it’s competition with its automatic belt tensioner line?
-This is absolutely false. Dayco has more coverage in both light duty and heavy-duty tensioners than any competitor. Our data is supported by a very detailed analysis of Polk V.I.O. data.
Q: Why did Dayco decide to use flat springs in their automatic belt tensioners?
-Tensioners were initially used on the demanding heavy-duty diesel engine drives where Dayco is the dominant tensioner supplier. Because of this, it only made sense to continue with this technology in our light duty line as well.
Q: When do you recommend replacing a serpentine belt?
-If you notice more than four cracks per inch in the belt it is recommended that the belt be replaced.
Q: Why do Dayco Poly Cog belts have transverse grooves on the bottom side?
-The transverse grooves dramatically increase belt life a minimum of 40% by reducing operating temperature up to 50 degrees F, 10 degrees C. They also reduce sensitivity to environmental factors such as dust and splash induced slip while reducing the harmonic noise. Other reasons include the fact that they increase flexibility in normal and backside bending as well as providing better pulley contact for less slippage.
Q: Why do Dayco Top Cog belts actually have the cogs?
-The Top Cog configuration increases flexibility and airflow around the belt. They also provide greater surface area to help the belt dissipate heat more efficiently and run better on small diameter pulleys.
Q: Is it wise to replace the tensioner and idler pulleys when replacing the timing belt?
-When replacing a timing belt, the timing belt system tensioner(s) and idler pulley(s) must also be examined to determine if they exhibit signs of wear or damage. If so these components should also be replaced. Approximately 50% of newly replaced timing belt failures are the result of non-replacement of faulty timing belt system tensioners and or idler pulleys.
Q: Are Dayco’s timing belt components equivalent to the Original Equipment parts?
-Dayco’s tensioners and idler pulleys are manufactured to meet the critical OE quality, fit, form and function requirements demanded by both domestic and imported vehicle manufactures to ensure long lasting peak performance.d.
Q: Do you recommend replacing all belts at the same time?
-Yes! If one belt on your vehicle has failed, you can bet that the others are not far behind. It is wise to replace all of your belts at the same time.
Q: When do you recommend changing your belts?
-You should begin checking your belts at 20,000 miles. Things to look for are cracks and splits, glazing, peeling, greasy buildup and splitting or missing sections.

Dayco has been manufacturing heavy duty radiator hose for over 50 years now, and is consistently striving to obtain new researches, developments, and production technologies that are necessary for the innovative design and production of Dayco radiator hose. A line of Dayco radiator hose that is capable of providing the most flexible connection for the anti-freeze coolant between the radiator and the engine. Some of the best selling radiator hoses by Dayco are the heavy duty straight radiator hose, gold label flex radiator hose, and the silicon radiator hose. All Dayco radiator hoses virtually feature a knitted reinforcement, synthetic EPDM construction with highest quality of woven mesh fabric and nitrile tube compounds that can withstand even the corrosive elements. The Dayco radiator hose also provides a high-strength and resistance to ozone and other damaging environmental elements. It also features a high-resistance outside coating that can endure oil, gasoline, and battery acids without chipping or breaking. If in some case your radiator hose needs to be replaced, try to use Dayco radiator hoses that are specifically made as an original equipment and replacement. In order to be assured that it is original Dayco radiator hose, only obtain it from a reputable online store like us.

Designed to carry the heated coolant from the engine block to the heater core under the dashboard and return it to the engine
Dayco’s standard heater hose is made for general service on light trucks and passenger cars. Constructed using all EPDM compounds and spiral reinforcement for high burst strength and excellent heat resistance of -40°F (-40°C) to +257°F (+125°C). This black cover hose is similar to SAE 20R3, Class D-2, and is specifically designed to be compatible with all common coolants and coolant additives.
Note: NOT suitable for fuel or oil transfer.

Designed for OHC and DOHC type engines
Dayco is recognized by the automotive industry as a world leader in the manufacture of timing belts. Dayco’s patented, self-lubricating fabric provides exceptional resistance to abrasion, resulting in extended pulley and belt life.The molded cog design runs quieter and is more economical than chain drives. Our premium, high modulus glass fiber non-stretch cord delivers precise length stability to keep the engine running smoothly over the life of the belt. The belt’s compounding and tooth configurations are designed for specific applications ranging from normal service to high performance, high temperature engines, where HSN compound is used. The part number includes three final digits that conform to industry standard numbering. Dayco Timing Belts meet all OEM performance specifications.

Designed for power transmission on multiple-accessory drives
This is the “cogged” version of the revolutionary multi-ribbed belt first developed by Dayco for the 1979 Ford® Mustang®. The multiple-rib design provides better belt-to-pulley contact for less slippage, so it lasts longer than conventional V-belts. “Multiple ribs” also eliminates the need for “matching”, and allows “controlled slippage” in shock overload situations, such as when the AC compressor kicks in. Today, as then, this belt sets the industry standard. The transverse groove design runs cooler (up to 50°F), and dramatically reduces rib cracking, thereby increasing the life of the belt by at least 40%. The grooved design provides flexural stress relief, for increased flexibility in both normal and backside bending. The grooves also render the belt less susceptible to environmental factors such as dust and splash-induced slip. Dayco’s superior manufacturing technology uses a rubber backing that maximizes load-carrying capability and minimizes the noise that is often associated with the competition’s belts. Torque-carrying capacity equals or betters conventional multi-rib belts. The cord is saturated with a specially formulated treatment that insures length and tension stability for the life of the belt. Dayco Poly Cog belts meet or exceed SAE J1459 and J1596 specifications.

Designed to provide the convenience of an application-specific, matched set of tensioner(s) and idler pulley(s) in a single package
Dayco’s Timing Belt Kits offer the convenience of tensioner, idler pulley and complete installation instructions (in English, French and Spanish) combined in one pre-packaged kit. Matched to the specific make, model and year of the automobile being repaired, each Dayco Timing Belt Kit component is guaranteed to fit and meet the specifications of the original equipment parts being replaced. In addition, each tensioner and idler pulley contained within the kit is individually packaged in “see-through” plastic bags so that the parts can be identified and compared to the original without compromising the integrity of the kit.

Designed to set proper tension and/or to absorb changes in loss of timing belt tension
A loss in timing belt tension may lead to catastrophic engine failure. It may also cause variations in engine temperatures, speed or the general wear and aging of the belt during crankshaft revolution. Maintaining tension at a constant level reduces noise, prevents belt flapping and ensures proper transmission efficiency throughout the entire service life of the belt. With the emergence of more interference engines in the Market, it has never been more important to change all components in the timing system.

Designed to replace serpentine and V-belt drive idler and tensioner pulleys
Dayco’s reputation for top performance idler and tensioner pulleys is the result of the advanced automotive technologies employed in the materials research, design engineering, and manufacture of our pulleys. Specially formulated glass-filled polymers insure a high strength, cooler running, wear resistant “plastic” pulley. The use of state-of-the-art 3-D computer aided design (CAD) and finite element analysis (FEA) guarantees the optimal design and maximum structural integrity for both plastic and steel pulleys. The manufacture of pulleys with smoother surfaces and tighter dimensional tolerances translates into less vibration and therefore longer belt life. Lifetime lubricated ball bearings and double high temperature seals assure peak bearing performance, the most critical element of a pulley’s service life.















