Time for a Drive Belt Replacement? Here's How to Do It Right

What Is a Drive Belt?

A drive belt (typically a serpentine belt) transfers power from your engine’s crankshaft to essential parts, such as the AC compressor, alternator, and water pump. 

Here’s how it works: 

When you start the car, your engine’s crankshaft rotates, driving the belt. As the belt moves, it turns connected accessory pulleys and generates power. The belt transfers this power to the alternator, AC compressor, and other engine accessories.

How to Replace a Failing Serpentine Belt

To replace a broken belt with a new one, you need a socket set and sometimes a special tool like a serpentine belt tool. You must also install the belt properly to ensure the connected engine accessories work. 

If you’re unsure about replacing this worn belt correctly, it’s best to hire a mechanic. 

Here’s how they’ll replace this car part: 

1. Click pictures of the current belt placement. If the old belt is out of place, they’ll refer to the owner’s manual for the correct placement.

2. Look for cracks, tears, or uneven grooves on the belt.

3. Inspect the belt tensioner for excess vibration or movement. A faulty tensioner will also need replacement.

4. Relieve the belt tension. Based on the belt type in your car, this step will be different.
   • If your car has a serpentine belt, the mechanic will use a special tool like a long-handled ratchet to rotate the automatic belt tensioner clockwise. This will relieve the tension, helping the damaged belt slide off.

   • If your vehicle has a V-belt system (accessory belt), they’ll adjust one of the pulleys to free the belt.

5. Remove the old belt.

6. Check other components like the idler and tensioner pulley for wear. Repair or replace them if needed.

7. Wrap the new belt around grooved and non-grooved accessory pulleys.

8. Rotate the automatic belt tensioner counter-clockwise until the spring releases and secures the new serpentine belt in place. If it’s a V-belt, they’ll manually tension it.

9. Ensure the belt alignment meets the owner’s manual specifications.

10. Start the vehicle’s engine to verify whether the replacement drive belt is working.

How Long Does a New Serpentine Belt Last?

A drive belt can last for about 50,000 to 100,000 miles. However, because it’s typically made of soft rubber and polymer, it can crack or tear over time. 

As part of preventative maintenance, schedule an inspection every 50,000 miles to catch a loose belt early.

7 Key Signs You Need to Replace the Bad Serpentine Belt

Symptoms that point to a broken serpentine belt include: 

1. Squealing sounds when you steer the car or turn on the air conditioner
2. AC vents blow warm air
3. Loss of power steering
4. Illuminated check engine or battery warning light
5. Engine overheating due to a failed water pump
6. Issues with power steering pump, water pump, and alternator pulley
7. Cracks or other belt wear (seen during visual inspection)

How Urgent Is a Serpentine Belt Replacement?

Extremely urgent.

A worn belt impacts not just your comfort but also your safety. If the drive belt fails, vehicle systems like the air conditioner won’t work, resulting in poor air conditioning and a stuffy cabin. 

You may also struggle with vehicle control due to power steering pump issues. Eventually, your car’s engine won’t start because the alternator will stop charging the battery.  

Apart from these issues, the loose belt can cause excess friction and extensive damage to parts like the water pump and air conditioning compressor. 

So, install a replacement drive belt immediately to prevent severe engine damage and costly repairs.

4 FAQs about Drive Belt Replacement

Here’s additional information on drive belts that you should know: 

1. How Much Does a Drive Belt Replacement Cost?

Most car repair shops and mechanics charge $90 to $250 to replace a broken belt. The cost can vary depending on the specific vehicle, location, and labor rate. 

Your expenses may increase if you need to replace an additional car part, such as a faulty air conditioning compressor or idler pulley. In fact, installing just the compressor could add between $810 and $1,210 to your bill. 

2. How Can You Maintain Your Drive Belt?

You can prolong the lifespan of your serpentine belt using these tips: 

• Install a high-quality, compatible serpentine belt. 
• Get the belt inspected at every oil change (or every 50,000 miles).
• Check the belt tension every three to six months.
• Follow a preventative maintenance schedule to identify a failing serpentine belt early.

3. What Are the Different Kinds of Drive Belts?

Modern cars have a single drive belt that powers the parts in the engine compartment, while older vehicles have multiple belts to do the same job. 

The different types of drive belts include: 

• V-belt (accessory belt): This short belt with V-shaped grooves is primarily found in older vehicles. Your vehicle may have more than one V-belt to run multiple components in the engine bay. Replacing V-belts can be tricky and time-consuming, as you may have to change multiple belts for balanced performance. 

• Serpentine belt: This long belt is typically found in newer vehicles. It’s a single belt that drives multiple devices in the engine compartment. Serpentine belts are relatively durable and usually last longer than V-belts.

4. Can You Replace a Bad Serpentine Belt or V-belt Yourself?

You can, but you shouldn’t. 

The difficulty level depends on the specific vehicle and belt type.

Older vehicles tend to have multiple V-belts, so there’s a higher chance of replacing more than one belt if worn. Modern cars with a serpentine belt require precise placement since a single belt drives several engine bay components. You also need to ensure proper belt tension to run the new belt.

A misstep in the replacement can prevent the belt from working efficiently, causing friction and overheating. Moreover, you need to check the tensioner and idler pulley for wear and replace damaged parts. 

If you’re new to car repairs, this task can be overwhelming. Call a mobile mechanic or visit the nearest repair shop to replace the broken serpentine belt with a new one.