For techs. By techs.

Repairs are unpredictable.
Parts shouldn’t be.

Tech Hub

We know you want the right part, the first time. No gimmicks, no lofty lingo, just the real deal. With honest, reputable advice, installation tips, and answers to technical questions that really matter. That’s why Dayco belts and front engine components are designed, tested and approved by techs, for techs. We understand the challenges you face and the unpredictable repair requests that may roll into your shop. Whether you’re looking for how-to articles and installation videos or would like training and ‘Dayco certification’ on a variety of topics, you’ll find the resources you need right here in Dayco’s Tech Hub. And if you don’t see the answer you’re looking for in one of our tech articles, tips or videos, feel free to email us directly at [email protected].

For Techs. By Techs.


Powersports Belt & Clutch Maintenance Tips

Every day our tech team sees post after post on social media forums asking about belt usage.

Replace serpentine belts, pulleys, tensioners toge...

Serpentine belts on today’s cars can have over 10 points of contact, creating very complicated...
Electric Water Pumps2

Addressing Common Installation Errors with Electri...

Electric water pumps are being used by OEMs more frequently thanks to a number of benefits.
Dayco TimingChainKit Installation

The Top Two Reasons Timing Chains Need Replacement

Timing chains don’t get a lot of attention – mostly because they are intended to perform for the life of the vehicle.

Industrial V-belt Cross Reference for 4L and 5L Be...

Dayco experts suggest switching from a 4L or 5L V-belt for some industrial/HVAC applications to a GOLD LABEL...

How to Properly Store Industrial V-belts

Many maintenance managers do not have a proper procedure for storing and handling power transmission belts...

How to Extend the Life of HVAC Belts

Belts used in HVAC applications are frequently found in exhaust and ventilation fans on rooftops. Often exposed to sunlight...

5 Reasons V-belts Don’t Last as Long as They Shoul...

Many maintenance managers report V-belt drives only last two-three months but the reality is premium heavy-duty...

Step-by-Step Industrial Belt Drive Maintenance

Belt drives are the most cost effective, reliable means of shaft-to-shaft power transmission speed change but...
TimingBeltTools Tips

Top 3 Timing Belt Tools and Tips

Timing belt maintenance requires precision and patience. One wrong move in belt alignment and the vehicle can experience a number of issues.

Timing Belts: 3 Signs of Failure

It’s often called the neglected belt yet can cause serious damage when overlooked.
DriveBelt Tips

Increase Performance on Your Industrial Belt Drive

If you have a belt drive system that is under-performing or you’re looking for improved drive life, below are Dayco’s top tips on enhancing performance.

How to Install a Harmonic Balancer

Harmonic balancers are used to help lessen the vibration of the engine. Maintenance and replacement are important. Belowe are the key steps...

The Top 8 Reasons Why Radiator Hoses Leak

Coolant hoses have a tough job – they move chemicals under pressure and massive amounts of heat so they can be more prone to failure.

CVT Belt Installation and Break-In

For powersports enthusiasts, there’s nothing worse than getting stranded due to a busted belt. That’s why belt replacement and...

Proper Car Cooling System Maintenance

It is extremely important to flush and refill the cooling system with the OE recommended coolant, whether you are just performing cooling system...
Balancer with Wrench

Three Reasons for Harmonic Balancer Replacement

A harmonic balancer is not just there to spin the rest of the pulleys on the engine. It’s designed to help smooth...
HighPerfCar BalancerAticleImage

High Performance Balancers vs. Stock Balancers

Many enthusiasts modify their vehicle’s engine for better performance and more horsepower...
Belr Rd

Belt Routing Diagrams

There are more than 16,000 belt routing diagrams available in Dayco’s Find Your Part search platform, covering millions of vehicles makes and models.
Tensioner Flat Spring

Belt Tensioners: Flat Spring Design Makes all the ...

The front-end drive system’s tensioner is designed to protect other components within the system and to help prevent premature failure of...

Belt Tools Help Reduce Comebacks

At Dayco, we’ve learned that some technicians aren’t checking total system alignment, they are only checking the belt itself. Below we outline two...

Front End Accessory Drive System Maintenance for H...

Just like many other components on today’s class 4-8 trucks, it’s important that mechanics look at the belt, pulley and tensioner as a whole system...

Signs of a Bad Belt Tensioner

Often times during a drive belt change, the tensioner may get overlooked. This can be problematic given the tensioner has a big job to do and...
Solutionsfor ProblemDriveSystems

Problematic Automotive Belt Drive Systems

Automotive belt drive systems have become significantly more complicated over the past 25+ years.
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Serpentine Belt Inspection

Most modern vehicles use serpentine belts that are now made with EPDM compounds. But EPDM belts wear differently than the earlier...

How to Tell when an Idler or Tensioner Pulley Need...

Did you know that one of the most common causes of serpentine belt failure is a pulley with worn bearings? That’s because a pulley’s job is...

How to Fix Serpentine Belt Noise

If a newly installed serpentine belt  is making noise, it is a sign of a problem within the engine’s front end drive system.
The EvolutionofSerpBelts

The Evolution of Serpentine Belts

Over the past 25 years, serpentine belts have changed considerably. Vehicles used to have multiple serpentine belts that only had...

Choosing the Right Engine Water Pump

How do you know you are getting the best quality when it comes to choosing a water pump? Here’s a few tips: Pick a pump that is...

Automotive Water Pump Repair

The purpose of a car’s water pump is to push coolant through the car's engine block, radiator and hoses to help pull heat away from the system.
Our head of product management walks through the role a harmonic balancer has in the engine, its key ...
Join our expert in the Dayco garage to learn how to accurately measure a belt without a part ...
Learn how to extend belt life with proper belt break-in and clutch maintenance from a resident Dayco powersports ...
Learn about the full line of Dayco POWER belts from one of Dayco’s very own powersports enthusiasts. He’ll ...
Electric water pumps help maintain fluid flow and keep components at safe temperatures but they can be installed ...
Find out the two main reasons why timing chains get replaced and what to do in each circumstance ...
Learn about inspection and installation intervals for heavy-duty water pumps from Dayco’s tech team. They share the top ...
Learn how to use the Dayco Awearness gauge during a proper belt inspection. This quick tutorial shows how ...
Go under the hood of a big rig with Dayco’s tech team members to learn about serpentine belt ...
Our ASE master tech and product specialist take you step-by-step through the installation of Dayco’s new two-piece tensioner ...
Dayco’s engine experts share basic belt tips to help make installation easier. Learn about maintenance intervals, belt wear, ...
One of Dayco’s product specialists explains the basics of belt installation for your ATV, UTV, side by side ...
Learn about the basic types of pulleys for today’s front end drive system and the eight key signs ...
Dayco’s resident ASE certified technician talks about why Dayco’s tensioner design, and its patented flat spring technology, is ...
Dayco’s resident engine experts show you all the tools needed to make timing belt installation easy – from ...
Learn the top two reasons water pumps fail after installation. Dayco’s engine experts also talk through torque, cooling ...

Not quite sure what’s causing a noise under the hood? Or have a drive belt giving you trouble? Search our most frequently asked questions to quickly find the answer you need.

It doesn’t matter if you drive a UTV, ATV or snowmobile,  you’ll need to break your new powersports CVT belt in using two heat cycles. After following proper installation procedures, slowly bring the machine to normal operating temperature without exceeding 3/4 throttle for about 20 minutes. If at all possible, stay on a flat terrain. Let the machine and belt cool down completely – it should take about 30 minutes. Then run your machine through the same process a second time. Lastly, make sure to check the belt height according to the  owner’s manual.

Dayco has more than 16,000 belt routing diagrams available on its Find Your Part search platform. If you come across a specific part number that does not have a diagram, and you can’t find it online or under the hood, feel free to use the Contact Us form and let us know the year, make and model and we’ll look it up and email it to you the same dayYou can also call our tech hotline and be connected directly with one of our team members – (800) 848-7902.

Beyond looking at the belt directly for physical signs of damage – such as swelling, cracks, or disfiguration – pay attention to how your car is functioning. Noise is often a telltale sign of a bad belt, as is an issue with your power steering or a/c. Your vehicle could even overheat due to a bad or worn belt.

Belt wear can be difficult to detect because newer belts made with EPDM rubber tend to wear like tire tread, where there is material loss from the rib surface. A new belt will have a traditional “V” profile in the grooves between the ribs. On a worn EPDM belt, however, the groove profile will have the appearance of a “UOne of the best ways to measure wear is by using a device like the Dayco Awearness Gauge, which helps you inspect a belt three different ways – by analyzing rib depth, checking rib profile and identifying cracks. If your belt has 90,000 miles or more, it is definitely time to change it. Check out our video for a stepbystep guide of measuring belt wear.

Without maintenance history of a car, the best possible way is to check CarFax for a repair history report, ask the previous owner, or look for a sticker under the hood indicating it has been changed. If all these fail, best course is to have a technician inspect it. Some OEMs recommend replacement as early as 30,000 miles, while others suggest maintenance around 100,000 miles. While timing belts are relatively inexpensive, if one breaks while the engine is running, it could cost thousands of dollars in damage so it’s important to be proactive. The best course of action is to change the belt if you cannot verify that it has been replaced at the OE suggested intervals.

Most timing belts will have two double dotted line marks and 4 to 6 solid marks. Double dotted lines are for the crankshaft, and the solid line is for camshaft alignment. Dayco includes detailed instructions with all timing kits so follow the instructions closely as they vary by make and model. Proper timing belt installation is critical to engine performance and long belt life. A belt installed incorrectly can cause immediate engine damage.

As long as nothing is removed from the routing system, like the A/C compressor, the OE stock belt length will still work. You can use our Find Your Part search or the Dayco app to find the recommended Dayco replacement belt.

When a belt breaks quickly after installation, it is likely due to one of the four reasons:

  1. It was not 100% seated in a pulley.
  2. Worn pulley bearings caused the belt to “walk off” the pulley surface.
  3. A damaged pulley could have ‘cut’ the belt.
  4. A malfunctioning tensioner caused belt misalignment and damage.

Be sure to check the tension and fit before completing the job and remember to change the pulley and tensioner when you replace a belt to avoid any issues like this.

There are two very distinct noises caused by different issues – one is a chirp, the other is a squeal. Your best course of action is to conduct a water test to see which one you are dealing with. With the vehicle idling, spray water on the belt’s rib surface. Then listen closely. If you hear a sharp, high-pitched, repetitive noise of short duration that is worse at low engine speeds (idle), you are dealing with a chirp alignment issue. If you hear a high-pitched noise that typically lasts several seconds and increases in volume as engine speed increases, you are dealing with a squeal, which is typically caused by a slip between the belt and pulleys. The noise will go away with the water spray if it’s a squeal, it will not if it’s a chirp. Check out our article on diagnosing belt noise for more.

There’s a few possible causes for a chirp: pulley misalignment, improper installation, extremely worn belt ribs, worn pulley bearings or contamination. We suggest the following solutions:

  • Check alignment of all pulleys, either with a straight edge or a laser alignment tool.
  • Ensure all accessory pulleys and brackets are tightened snug to mounting surfaces.
  • Inspect and replace all accessories/pulleys that are difficult to rotate (i.e. rough/seized bearings) or show excessive wobble/free rock.
  • Double check the power steering pulley and harmonic balancer, as they are often a common cause for misalignment.

A squeal is usually caused by low bely tension or contamination. To rectify the problem, we suggest the following steps:

  • Properly tension manual applications during installation (35 lbs. per rib) and then re-tension after 5 minutes of run-in (30 lbs. per rib). This allows the belt to seat in the pulleys.

On vehicles with automatic belt tensioners, the tensioner pulley should turn freely without binding. The tensioner arm should move smoothly through its entire range of motion and there should be adequate tension. Always check the tensioner bearing for noise and wear. Replace any tensioner where the bearing feels rough or the pulley has signs of excessive run-out (wobble).

  • With the belt removed, inspect all accessory pulleys and idlers to ensure free and smooth rotation. If there is binding or rough rotation (dry bearing), then the pulley and/or accessory should be replaced.
  • Check for contamination. If the belt has been in contact with motor oil, power steering fluid, antifreeze or any other petroleum-based lubricant, it will cause the EPDM belt to swell, leading to noise. Other than washer fluid, replace any serpentine belt that has been oil soaked. NEVER try to solve issues with belt dressing.

Regular inspection of all drive belts, tensioners and accessories should be recommended once the vehicle passes 60,000 miles. And when the belt is worn and ready for replacement, which is typically around 90,000 miles, the pulley and tensioner should also be replaced. That’s because the drive works as a system. Replacing only the belt will often result in short belt life because the tensioner likely has worn springs or the pulleys’ bearings are worn and causing a slight misalignment. Even the pulleys themselves can wear and cause reduced belt life and/or noise. Replacing the entire front end accessory drive system will result in another 90,000 miles of trouble free driving.

Belt wear can be difficult to detect because newer belts made with EPDM rubber tend to wear like tire tread, where there is material loss from the rib surface. A new belt will have a traditional “V” profile in the grooves between the ribs. On a worn EPDM belt, however, the groove profile will have the appearance of a “U”. One of the best ways to measure wear is by using a device like the Dayco Awearness Gauge, which helps you inspect a belt three different ways – by analyzing rib depth, checking rib profile and identifying cracks. If your belt has 90,000 miles or more, it is definitely time to change it. Check out our video for a step-by-step guide of measuring belt wear.

It could be. The water pump is responsible for the cooling system and pulling heat away from the engine. If the pulley is loose or if you notice signs of a leak around the water pump’s weep hole, it’s time for a change. Be sure however that when replacing the water pump, you also drain, flush and refill the cooling system with the OE specified coolant mix. The seal in the pump is designed only to work with this chemistry. This is the #1 cause of leaks in new water pumps. Most modern vehicles use organic acid coolants.

It’s best practice to change both components at the same time because they usually wear out at the same pace and if one fails or is failing, the other is likely not far behind it. They are both part of the same system and need to function at optimal levels as well.

The Dayco Underdrive and overdrive balancers are a great way to increase the performance of your factory supercharged car. These balancers feature pulleys that are either larger or smaller than the factory supercharger pulley. Spinning the supercharger faster will increase the amount of supercharger boost pressure and in turn, increase the horsepower of the engine. Installing these pulleys does require professional dynamometer calibration of the engine computer by a qualified shop. And additional parts such as larger fuel injectors may be needed to take full advantage of the increased boost. Dayco offers professional advice and assistance in choosing the right balancer for your engine build by calling our tech line or using the contact us form on our website.

You’ll want to replace the balancer if you notice excessive vibration, crankshaft oil leaks, or deteriorated rubber.

The additional keyway is they if you plan to use a high-volume supercharger. A second keyway needs to be machined in the crank snout. If you do not need the second keyway, a little dab of silicone RTV in the unused keyway is all you need.

The PowerBond by Dayco SS series uses the factory balance weights; The race balancer is for engines with zero balance. If you need help choosing the correct balancer for your engine build, please contact the Dayco tech team at (800) 848-7902 for advice and part numbers.

On some late model GM engines, the balancer is a press fit instead of using a keyway to hold it in place. This works fine until a supercharger kit is added. The additional stress of the belt driven supercharger requires either a keyway be machined or the usa balancer pin kit, which is available from many speed shops.

The regular harmonic balancers are not meant for race cars but they offer engine builders and technicians a high-quality replacement to standard OEM balancers for everyday vehicles. Racing balancers are made from more robust materials like forged steel so they can withstand much higher RPMs.

The Dayco balancer fits a multitude of applications, some of which do require the keyway. If yours does not, you can fill in the keyway with silicone.

A belt tensioner should be replaced if any of the following issues are noted:

  1. You hear noise or feel resistance as that could be a sign of potential bearing failure.
  2. The belt is not tracking correctly as that could mean a loss of tension.
  3. There is sticking or notchy movement. With the belt removed, use a tool to move the tensioner through its entire range of motion. It should move smoothly from stop to stop without any movement between the tensioner body and arm.
  4. There is metal to metal contact or broken/cracked tensioner stops.

There are several signs a pulley is no longer functioning properly. First, check for free rock. There should be no movement or play from side to side. Next, look for misalignment. It will cause a belt chirp noise and is often the result of worn bearings. Spin the pulley with the belt removed, if it spins more than one revolution, the bearing grease is depleted and the pulley should be replaced. Roll the pulley by hand to feel for rough spots during rotation. You’ll also want to check for physical damage like cracked or broken pulleys, discoloration, surface build-up or excessive wear. Finally, a pulley with seized bearings is also a sign replacement is needed.

Unlike laser tools with attachments, Dayco’s tool has an aluminum body with magnets that secure it into the grooves of the reference pulley (usually the crankshaft pulley), ensuring a stable stage for accurate laser projection. The target component is also magnetic so it easily attaches and aligns with the grooves. Once turned on, the laser will project a line – not just a dot – which is an advantage over other laser tool designs. This projected line makes it possible to identify both axial and angular misalignment. Axial misalignment means the pulley is not positioned on the shaft properly. Angular misalignment is caused by a severely worn bearing within the pulley. Before using this tool, always make sure to disconnect the vehicle’s battery. Also, remove the vehicle’s serpentine belt before inspecting the accessory drive system.

The force of the belt being installed can often push a pulley out of alignment. When the system is relaxed, it might not be apparent. Start by checking all bearings in the pulleys and tensioner for any side to side play. Rotate the tensioner stop to stop while observing the tensioner body for movement. There should be none. Then, inspect the grooves in the tensioner pulley and idler pulleys for contamination or wear. If you are still having issues, conduct a noise test. With the vehicle running, spray water on the belt. If you hear a chirping noise, there is misalignment somewhere in the system. If the belt is squealing, where the noise goes away and returns quickly, there is an issue with tension and the tensioner should be replaced.

Most hoses require replacement – regardless of where they are at on a vehicle – once every four years. However, we recommend following the OE specifications on replacement intervals.

It’s often difficult to look at a hose and know whether it’s faulty. Some physical signs a hose is bad is when it’s collapsed, broken, if it’s brittle or stiff. Most hoses are pliable and soft so anything other than that should indicate the need for further inspection. Other signs that suggest a hose is bad is if you see signs of leaks or bulging around the connection to the clamp.


Welcome to the TechKNOW by Dayco™  online training series developed by our team of ASE certified tech experts.

This program is designed for counterstaff, sales team members and new technicians, and includes short 5-10 minute webinars to help participants better understand the benefits of Dayco’s belts and components, and address some of the top installation problems that occur with front engine system maintenance and replacement. Each video is accompanied by a downloadable training guide – which includes key data points and a quiz to test your knowledge.

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Meet the Tech Team

Want to meet the experts behind all the technical advice, installation videos and repair tips we share? Meet Dayco’s tech team. With almost 150 years of combined on-the-job experience, our crew of ASE certified techs, former shop owners, product specialists and engineers have one goal – to make the installation process as easy as possible. These guys know time is money and less time struggling through a repair means more money in your pocket.


Jay Buckley

AKA “Crew Chief”

Years of Experience: 35 

ASE Certified Master Technician, Former Shop Owner 

An ASE Master Technician for over three decades and a repair shop owner for almost 25, Jay Buckley is the head of product management and training for Dayco. His experience includes technical writing, research, hands on training, repair and diagnostic work, events, video training and more. He is a state of Michigan certified master technician, HD diesel technician and motorcycle mechanic. With almost a half-century of experience, his infatuation with vehicles started at 11 years old with his neighbor’s ’67 Shelby Mustang. Now, more than 50 years later, he is still a self-professed gearhead and an amateur racer. He loves time in the garage and on the track, rebuilds cars and restores vintage MX bikes.


Jerry DeGelder

AKA “Tech Guy”

Years of Experience: 28 

ASE Certified Technician 

Jerry DeGelder’s connection with cars started alongside his dad, working on the family car. He’s been ASE certified for nearly 22 years now and has an associate’s degree in Automotive Technology. Pursuing a childhood dream of becoming a teacher, Jerry went through the training needed to become a technical trainer in the automotive industry in 1995. He plays an active role on Dayco’s technical team, conducting in-person training sessions and fielding calls from technicians looking for specific parts or solutions to mechanical issues.


Jerry Reeves

AKA Engineering Nerd

Years of Experience: 20 

Mechanical Engineer, Former State of Michigan Certified Technician, Weekend Road Racer

An aftermarket industry veteran, Jerry has almost two decades of program management and product launch experience. Passionate about all things automotive and powersports, Jerry Reeves earned a mechanical engineering degree from Kettering University after taking two years of automotive repair in high school – he went from working on cars and parts to designing them. He’s been state certified in front end, suspension and steering systems, engine tune up and performance, engine repair and brakes and braking systems. He has a heavily modified 1974 Chevy Nova and motorcycle that he races, and one of his greatest memories was participating in the 2,300-mile Hot Rod Power Tour with his two sons.


Jon Crawford

AKA “Performance Champ

Years of Experience: 12 

Mechanical Engineer, Weekend Road Racer

As an automotive, motorcycle, snowmobile, and ATV enthusiast, it’s no surprise that Jon Crawford is a product manager and tech expert for Dayco. Tinkering on vintage Corvettes and small engines since he was 8 years old, Jon has well over a decade of real-world automotive aftermarket experience. He earned his mechanical engineering degree from University of Toledo and has scored multiple national championships in motorcycle amateur road racing. Never one to pass up an opportunity to fix something under the hood, his favorite automotive memory was restoring his late father’s 1973 Corvette and driving it to the Woodward Dream Cruise.


Chad Suffel

AKA “Ironman”

Years of Experience: 13  

Former Package Engineer, Avid DIYer, Current Product Manager

Chad Suffel has been getting fired up about cars since he was young. It all began alongside his dad wrenching on an LS1 Camaro, and grew stronger as he headed into college, where he graduated with a B.S. in Packaging from MSU. A true hot rodder, DIY tuner and avid motorcyclist, Chad has not only gotten his hands dirty on a number of machines here at Dayco, he also leads the development of new tensioners, pulleys, water pumps and timing chain kits. If you’re trying to track him down, check outside first – he’s either in the garage tinkering on his motorcycle, or off running, swimming or biking absurdly long distances, as he just recently competed in his 2nd Ironman.


Hassan Mourad

AKA “Diagnostic Doctor”

Years of Experience: 16  

State of Michigan Certified Master Technician

Hassan’s fascination with cars began his freshman year of high school thanks to a very passionate auto tech teacher. As a state of Michigan master tech and a product evaluation expert for Dayco, he’s well versed in solving diagnostic issues and benchmarking new products. If he’s not at work or under the hood wrenching on the next project car, you may find him at the track, participating in amateur racing days.