Alternator pulley: work, change and price

The alternator pulley forms the link between the alternator and the crankshaft, taking over the accessory belt. Thus, it participates in the supply of electricity to the engine accessories, as well as in the recharging of the battery. The alternator pulley is usually replaced at the same time as the seat belt kit.

🔍 What is an alternator pulley?

Role alternator pulley should get strap for accessories, also called alternator belt. The latter is driven by crankshaft and then allows the generator itself to be driven through the alternator pulley.

However, it is the generator that is used in the engine to generate electricity to recharge the battery and power the car's accessories: car radio, air conditioning, power steering, etc. This is why we are also talking about the accessory strap.

There are different types of alternator pulleys:

• La generator decoupling pulley : Prevents transmission jerkiness and is designed according to the same principle as the damper pulley;
• La Alternator pulley with poly-V-profile : has circumferential grooves and a smaller diameter than older trapezoidal pulleys;
• La switchable alternator pulley or overrunning clutch: reduces jerking during transmission between the crankshaft and the generator;
• La alternator pulley with trapezoidal profile : This is the negative imprint of the V-belt generator. It is rarely used today, so you won't find it on most new cars.

📆 When to change the alternator pulley?

The alternator pulley is part belt accessory kit... The accessory belt, like the timing belt, is a wearing part that must be replaced. every 150 kilometers O. In this case, we replace tension rollers belt, alternator pulley or even damper pulley.

Please note that alternator belt replacement intervals are different and that replacement, like alternator pulley replacement, is mainly based on the condition of the kit. So first and foremost, watch for any symptoms that indicate it is time to replace the alternator pulley and the rest of the accessory belt kit.

🚘 What are the symptoms of the HS alternator pulley?

Over time and with use, the alternator pulley can jam or wear out. However, this can sometimes be reduced depending on the electrical needs of the vehicle. When it is damaged, it creates problems with the alternator and therefore with the power supply.

Here are the symptoms of a broken or faulty alternator pulley:

• Abnormal noises from accessory belt ;
• Accessory strap who is jumping ;
• Difficulty getting started ;
• Battery indicator is on ;
• Accessory problems : headlights, air conditioner, power steering, etc.

👨‍🔧 How to replace the alternator pulley?

If the alternator is easy to access, replacing the alternator pulley requires removing not only the alternator but also the accessory belt. Therefore, it will need to be reassembled and re-tensioned correctly thanks to the tensioning roller, which now systematically works automatically.

Material:

• Tools
• Alternator pulley

Step 1: remove the generator

Find a generator that may be located differently depending on the engine. It is usually located closer to the front. Remove the plastic cover from the engine and the battery cover if your vehicle has one, then disconnect the battery.

To disassemble the generator, disconnect its electrical plug and cable, then remove the nut and bolts that secure the generator. Loosen the alternator belt using the tensioner and remove it before removing the alternator.

Step 2: disassemble the pulley

The pulley is removed with a special head. First remove the plastic cover from the alternator pulley, then insert the socket and secure it with one hand while loosening the pulley with the other. Finish loosening to remove.

Step 3: Install a new alternator pulley

Make sure the new alternator pulley matches the old one (same type and same dimensions). Then install it using the special socket and tighten to the torque recommended by the manufacturer. Place the plastic cover over the pulley and screw it on.

Then assemble the generator. Reconnect its plug and electrical cable, tighten the bolts, then replace the alternator belt and tension it correctly. Finally, reconnect the battery and start the engine to make sure your vehicle runs smoothly.

💳 How much does the alternator pulley cost?

The price of an alternator pulley varies greatly depending on the brand, type of pulley and, of course, where you buy it. You will find it in auto parts stores. Count on average From 30 to 50 €.

The cost of replacing the alternator pulley increases the cost of some of the labor. Depending on the hourly wages and the price of the part, calculate From 60 to 200 € and up to 300 euros including the alternator belt.

Now you know all about the role and operation of the alternator pulley! As you read in this article, the alternator belt must be loosened and removed to replace this pulley. So entrust this operation to a trusted mechanic!