How to Replace a Serpentine Belt: 13 Steps (with Pictures) (2024)

Explore this Article

parts

1Finding the Serpentine Belt

2Relieving the Tension on the Serpentine Belt

3Replacing the Serpentine Belt

Other Sections

Video

Related Articles

References

Article Summary

Co-authored byDuston Maynes

Last Updated: January 12, 2024

The serpentine belt in most modern vehicles transfers power from the crank pulley to the various accessories mounted on the engine. A worn or damaged serpentine belt can fail to adequately transfer the power, leaving your alternator, power steering, and air conditioning failing to function. If your serpentine belt needs to be replaced, it can be done using only common hand tools.

Get Car Support Solve Any Problem

How to Replace a Serpentine Belt: 13 Steps (with Pictures) (1)

Hi there! Do you have a question about how to diagnose or fix a problem with your car? I’ve read the manual so you don’t have to. Select your make, model, and year, then ask away!

*

*

Part 1

Part 1 of 3:

Finding the Serpentine Belt

Download Article

  1. 1

    Pull the hood release inside the cabin of the vehicle. To access the serpentine belt, you will need to open the hood of the vehicle. The hood release can usually be found near the door on the driver's side of the vehicle.

    • With the hood released, you will also need to release the safety latch located at the front of the vehicle.
    • If you are having difficulty locating the hood release or safety latch, refer to your owner's manual for guidance.
  2. 2

    Disconnect the battery. You should always disconnect your battery before starting an automotive project. Use the appropriate sized wrench or socket to loosen the nut holding the black ground cable on the negative terminal of the battery.

    • Slide the cable off of the terminal and tuck it to the side of the battery.
    • You will not need to disconnect the positive terminal.

    Advertisem*nt

  3. 3

    Locate the serpentine belt. Depending on the engine in your vehicle, the serpentine belt may be located at the front of the engine bay, or it may be along one side.[1] There may be engine covers in the way, so be prepared to remove them if need be.

    • Engine covers may be held in place by plastic clips, so take care not to break them as you remove the covers.
    • If you cannot find your serpentine belt, refer to the service manual for your specific vehicle.
  4. 4

    Look for signs of damage or wear on the belt. Once you have located the serpentine belt, inspect it visually for signs of damage. If the belt is frayed, coming apart, or has marks that indicate that it has been rubbing on something, it will need to be replaced.[2] It is usually easy to determine if a belt needs to be replaced, as they tend to crack or lose chunks when they are overworn.[3]

    • Most serpentine belts need to be replaced every 40,000 to 70,000 miles.
    • If there are signs of the belt rubbing on something, make sure to identify and repair whatever it was rubbing on to avoid damaging the new belt.
  5. 5

    Find the serpentine belt routing diagram. Many cars come with a sticker in the engine bay that shows exactly how the serpentine belt is supposed to be routed through the various pulleys on the engine. If your vehicle does not have a sticker, you will need to find another way to remember how the belt should be run.

    • Look in the owner's or service manual for your specific year, make and model vehicle for a diagram.
    • You can also take a picture of the existing belt with your cell phone to use as a guide when installing the new one.
  6. Advertisem*nt

Part 2

Part 2 of 3:

Relieving the Tension on the Serpentine Belt

Download Article

  1. 1

    Determine if there is a belt tensioner pulley. Depending on the application, your serpentine belt will either have tension placed on it using a movable bracket or an auto tensioner pulley. This pulley uses an internal spring to apply consistent pressure to the belt at all times.[4]

    • If your vehicle does not have a tensioner pulley, the alternator bracket is likely how tension is set on the belt.
    • Refer to your vehicle's service manual to confirm what type of tensioner your vehicle uses if you aren't sure.
  2. 2

    Use a wrench to relieve the auto tensioner. Auto tensioners have either a hole that will fit a half inch drive ratchet, or a bolt you can use a socket to apply pressure to. Insert the wrench or place the socket over the bolt on the tensioner and twist it away from the belt to relieve the tension on it.[5]

    • Depending on the positioning of the tensioner pulley you may need to twist the tensioner clockwise or counterclockwise.
    • Be sure to use the right size socket to avoid stripping the bolt head on the tensioner.
  3. 3

    Loosen the bolts in the alternator bracket. If your vehicle uses the alternator bracket to apply tension to the belt, loosen the two bolts that pass through the long eyelets on the bracket. As you loosen the bolts, the tension on the belt will likely move the alternator toward the engine and relieve the pressure.[6]

    • Loosen the bolts enough to move the alternator, but don't remove them.
  4. 4

    Pull the belt off of the pulleys. With the tension relieved from the belt, pull it off of the pulley that has been placing tension on it, then remove it from the around the rest of the pulleys on the engine.[7]

    • If the belt is severely damaged, be sure to remove any parts that may have come off of it as well.
  5. Advertisem*nt

Part 3

Part 3 of 3:

Replacing the Serpentine Belt

Download Article

  1. 1

    Compare the new belt to the old one. Look at the new belt in comparison to the old one to be sure they are the same width and have the same number of ribs going across the belt horizontally. The old belt may be slightly longer than the new one due to stretching.[8]

    • If the new belt is not the same width as the old one, it is the wrong belt.
    • Make sure the new belt doesn't show any signs of damage from the factory or it may tear after you install it.
  2. 2

    Route the belt through the pulleys. Run the new belt through the pulleys in exactly the same way the old one was. Refer to the belt diagram in your vehicle's owner's manual or the picture you took of the belt before removing it to guide you.[9]

    • The belt should be long enough to route around all of the pulleys except the tensioner until you relieve the pressure on it.
    • If the belt is loose after routing it, it is either the wrong size belt or you've routed it incorrectly.
  3. 3

    Apply pressure on the auto tensioner and put the belt over it. Use the same wrench to loosen the auto tensioner pulley, then pull the belt over it. Once the belt is in place, release the pressure on the tensioner so it holds the belt in place.[10]

    • It may be difficult to apply pressure to the tensioner and route the belt, so you may want to ask a friend to help.
  4. 4

    Increase the tension on the belt. If your vehicle does not have an auto tensioner, insert a pry bar or piece of wood between the alternator and the engine. Run the belt over the alternator pulley, then use the bar to pry the alternator away from the engine and increase the tension on the belt. Tighten the bolts again as you apply tension.[11]

    • You may need help tightening the bolts as you apply pressure to the alternator.
    • Be careful not to pry against anything plastic in your engine bay to avoid breaking anything.
  5. Advertisem*nt

Expert Q&A

Search

Add New Question

  • Question

    How do I know if I need to replace my serpentine belt?

    Duston Maynes
    Automotive Repair Specialist

    Duston Maynes is an Automotive Repair Specialist at RepairSmith. Duston specializes in leading a team that handles a variety of automotive repairs including replacing spark plugs, front and rear brake pads, fuel pumps, car batteries, alternators, timing belts, and starter motors. Duston holds an Associate’s degree in Automotive/Diesel Technology from The Universal Technical Institute of Arizona and is a Certified Diagnostic Technician and Automobile Mechanics Technician through BMW STEP. RepairSmith received The 2020 Big Innovation Award by Business Intelligence Group and The Startup of the Year by the American Business Awards. RepairSmith was also included in Built in LA’s 50 Startups to Watch and The Business Intelligence Group’s 52 Names Leading the Way in Customer Service. RepairSmith offers in-home services to provide car owners convenient and complete auto repair everywhere.

    Duston Maynes

    Automotive Repair Specialist

    Expert Answer

    Although serpentine belts last quite a bit, it's important to check on them every once in a while. To see if there's any problem, check if the outer side of the belt is looking glassy and if the inside of the belt is cracking. These are both good indicators that the serpentine belt needs to be replaced.

    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support wikiHow

    YesNo

    Not Helpful 2Helpful 9

  • Question

    What happens if the serpentine belt breaks?

    Duston Maynes
    Automotive Repair Specialist

    Duston Maynes is an Automotive Repair Specialist at RepairSmith. Duston specializes in leading a team that handles a variety of automotive repairs including replacing spark plugs, front and rear brake pads, fuel pumps, car batteries, alternators, timing belts, and starter motors. Duston holds an Associate’s degree in Automotive/Diesel Technology from The Universal Technical Institute of Arizona and is a Certified Diagnostic Technician and Automobile Mechanics Technician through BMW STEP. RepairSmith received The 2020 Big Innovation Award by Business Intelligence Group and The Startup of the Year by the American Business Awards. RepairSmith was also included in Built in LA’s 50 Startups to Watch and The Business Intelligence Group’s 52 Names Leading the Way in Customer Service. RepairSmith offers in-home services to provide car owners convenient and complete auto repair everywhere.

    Duston Maynes

    Automotive Repair Specialist

    Expert Answer

    The belt can get caught in the crank, obstructing the system and damaging the motor.

    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support wikiHow

    YesNo

    Not Helpful 2Helpful 9

  • Question

    How do I replace the crank shaft pulley?

    How to Replace a Serpentine Belt: 13 Steps (with Pictures) (22)

    Community Answer

    It's impossible to say without knowing the year, make, or model of your vehicle. You should be able to do a search online to find some tips on replacing parts for your specific vehicle.

    Thanks! We're glad this was helpful.
    Thank you for your feedback.
    If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even $1 helps us in our mission.Support wikiHow

    YesNo

    Not Helpful 4Helpful 6

See more answers

Ask a Question

200 characters left

Include your email address to get a message when this question is answered.

Submit

      Advertisem*nt

      Video

      Tips

      Submit a Tip

      All tip submissions are carefully reviewed before being published

      Submit

      Thanks for submitting a tip for review!

      You Might Also Like

      How toChange the Oil in Your CarHow toChange Transmission Fluid
      How toRefill Brake FluidHow toCheck the Fluids in a CarHow toReplace Disc BrakesHow toAdd Transmission FluidHow toBleed a Slave CylinderHow toChange a Timing BeltHow toTest a Fan ClutchHow toPut on an Alternator BeltHow toChange a Timing ChainHow toReplace Universal JointsHow to Fit a Clutch Plate: Everything Home Mechanics Need to KnowHow toClean a Transmission Solenoid Valve

      Advertisem*nt

      More References (2)

      About This Article

      How to Replace a Serpentine Belt: 13 Steps (with Pictures) (34)

      Co-authored by:

      Duston Maynes

      Automotive Repair Specialist

      This article was co-authored by Duston Maynes. Duston Maynes is an Automotive Repair Specialist at RepairSmith. Duston specializes in leading a team that handles a variety of automotive repairs including replacing spark plugs, front and rear brake pads, fuel pumps, car batteries, alternators, timing belts, and starter motors. Duston holds an Associate’s degree in Automotive/Diesel Technology from The Universal Technical Institute of Arizona and is a Certified Diagnostic Technician and Automobile Mechanics Technician through BMW STEP. RepairSmith received The 2020 Big Innovation Award by Business Intelligence Group and The Startup of the Year by the American Business Awards. RepairSmith was also included in Built in LA’s 50 Startups to Watch and The Business Intelligence Group’s 52 Names Leading the Way in Customer Service. RepairSmith offers in-home services to provide car owners convenient and complete auto repair everywhere. This article has been viewed 195,926 times.

      26 votes - 59%

      Co-authors: 9

      Updated: January 12, 2024

      Views:195,926

      Categories: Transmission Parts

      Article SummaryX

      To replace a serpentine belt, start by locating the old belt at the front or side of your engine bay. Then, use a wrench to relieve the auto tensioner so you can pull the belt off of the pulley system. If your vehicle doesn't have an auto tensioner, look for an alternator bracket and loosen the bolts in it instead. Next, get a new serpentine belt with the same width and number of ribs as the old one, and route it through the pulley system. Finally, apply tension to the new belt by tightening the auto tensioner or alternator bracket. To learn how to tell if an old serpentine belt needs to be replaced, scroll down!

      Did this summary help you?

      In other languages

      Spanish

      • Print
      • Send fan mail to authors

      Thanks to all authors for creating a page that has been read 195,926 times.

      Reader Success Stories

      • How to Replace a Serpentine Belt: 13 Steps (with Pictures) (35)

        Quincy Tha Billionaire

        Jun 30, 2020

        "I'm grateful it didn't take long."

      Did this article help you?

      Advertisem*nt

      How to Replace a Serpentine Belt: 13 Steps (with Pictures) (2024)

      FAQs

      What else should be replaced when replacing serpentine belt? ›

      In addition to the belt itself needing to be periodically replaced, the tensioner pulley (and the idler pulley, if there is one) spins on bearings, and over time, they wear out.

      How many hours does it take to replace a serpentine belt? ›

      Plus, replacement is relatively easy, and if you're wondering how long does serpentine belt service take, it's less than an hour for most vehicles.

      How do you find a serpentine belt routing diagram? ›

      A: Commonly a belt routing diagram sticker is on the underside of the hood or in the engine compartment. If there is no diagram, make a sketch of the belt and pulleys before removing the belt. This will help you re-route the new belt correctly.

      Can I replace a serpentine belt by myself? ›

      Serpentine belt replacement is easy because today's automatic drive belt tensioners eliminate the need to loosen bolts or pry components into position for retensioning. Just rotate the tensioner, remove the old belt and install a new one.

      What tool do I need to loosen serpentine belt? ›

      There are only a few things you'll need to replace a serpentine belt: a new belt, a belt tensioner tool and maybe a socket wrench. These things should be easy to find at an auto parts store. Gloves and eye protection never hurt either. Every car engine is different, even engines from the same auto manufacturer.

      Should I replace pulleys when replacing a serpentine belt? ›

      We suggest technicians change a pulley whenever a timing belt or serpentine belt is changed and vice versa, but there are eight key warning signs to look out for when a pulley goes bad: Rock – Rock the pulley back and forth. There should be no movement or play from side to side.

      Should you replace the water pump when replacing a serpentine belt? ›

      It's a good idea for customers to replace both the water pump and the timing belt simultaneously so that both parts are brand new and will wear at the same time.

      What noise does a bad serpentine belt make? ›

      One of the earliest signs of a failing serpentine belt is a high-pitched squealing or whining noise, especially during engine startup or when turning the steering wheel. This noise is typically caused by the belt slipping on the pulleys due to reduced tension or deterioration.

      How much does it cost to replace a serpentine belt? ›

      The average cost for serpentine belt replacement is between $109 and $134. Labor costs are estimated between $57 and $72, while parts range between $52 and $62. Whether you go to the mechanic or do it yourself, replacing a serpentine belt costs $58 to $126.

      How many years does a serpentine belt last? ›

      How long does a serpentine belt last? Being made of durable rubber, a serpentine belt can last anywhere from around 50,000-100,000 miles. Learn when to replace a serpentine belt and more with the service center at Westbrook Toyota.

      How do I know which serpentine belt to buy? ›

      You can find the correct size of serpentine belt for your car in the owner's manual or by using an online belt sizing tool. If you are unsure about the size of the serpentine belt you need, it is best to consult a mechanic or an auto parts store.

      Does it matter which way a serpentine belt goes? ›

      Because nearly all serpentine belts are symmetrical, a new belt's direction of rotation usually doesn't matter. What does matter, though, is that the new belt is routed correctly around the pulleys.

      How do I find my serpentine belt number? ›

      The second, and lesser known one, is a global industry standard number that indicates the size of the belt. This industry standard number, frequently denoted as the “PK” number, is printed next to the manufacturer's part number on almost every serpentine belt produced, and can be seen in the examples below.

      Do you need a tool to replace serpentine belt? ›

      Tools/Supplies Needed: ratchet and socket set. torque wrench. new replacement belt.

      How much does it cost to get a serpentine belt changed? ›

      The average cost for serpentine belt replacement is between $109 and $134. Labor costs are estimated between $57 and $72, while parts range between $52 and $62. Whether you go to the mechanic or do it yourself, replacing a serpentine belt costs $58 to $126.

      How did my serpentine belt come off? ›

      Top causes of serpentine belt failure:

      Misalignment pulleys or tensioner: If the belt is not properly aligned on the pulleys, it can wear unevenly or slip off entirely, leading to its premature failure.

      Top Articles
      Latest Posts
      Article information

      Author: Prof. An Powlowski

      Last Updated:

      Views: 6189

      Rating: 4.3 / 5 (64 voted)

      Reviews: 95% of readers found this page helpful

      Author information

      Name: Prof. An Powlowski

      Birthday: 1992-09-29

      Address: Apt. 994 8891 Orval Hill, Brittnyburgh, AZ 41023-0398

      Phone: +26417467956738

      Job: District Marketing Strategist

      Hobby: Embroidery, Bodybuilding, Motor sports, Amateur radio, Wood carving, Whittling, Air sports

      Introduction: My name is Prof. An Powlowski, I am a charming, helpful, attractive, good, graceful, thoughtful, vast person who loves writing and wants to share my knowledge and understanding with you.