QA

Question: How To Change Alternator Pulley

How much does it cost to replace an alternator pulley?

There is an average cost for a drive belt idler pulley replacement. Labor costs are between 64 and $81 while parts are between $79 and $83. Taxes and fees are not included in the estimate.

Can I put a smaller pulley on my alternator?

Using a smaller pulley will speed the rotor up, and the alternator will produce more power.

How do I know if my alternator decoupler pulley is bad?

Diagnosis is fairly simple: look, listen and feel It should not be fluttering, dithering or vibrating excessively. Look for signs of grease around the pulley indicating a bad seal. If you can get a view inside the alternator, the rotor should continue to spin down when you shut off the engine.

How long does an alternator pulley last?

The expected life span of a decoupler type pulley, according to the website of the company that manufactures them, is 40,000 to 60,000 miles.

Should my alternator pulley spin freely?

It should turn quite easily but more important is it should be smooth. Very smooth. New bearings will sometimes feel a bit stiff and not turn freely because of the new seals and new grease that is in them. However that is ok as long as they are smooth.

How much does it cost to replace a pulley?

It will cost between $125 and $380 to have your pulley replaced. The labor should cost between $45 and $155 and the parts should cost between $85 and $225.

How long does it take to replace a pulley?

If you are doing the job at home, give yourself about four hours to change all the parts. You will need the following tools and parts: Replacement idler pulley. Tensioner pulley.

How long does it take to replace a tensioner pulley?

What Is Tensioner Pulley Replacement? Replacing the pulley should only take an hour or two, and the parts will vary in cost from one type of car to the next.

What causes a pulley to break?

#1 – Pulley Old and Worn Out The idler pulley is constantly spinning along with the drive belt. This creates wear and tear on the pulley after years of doing this repeatedly.

What is alternator pulley ratio?

The pulley ratio is the ratio between the outer diameters of the engine drive pulley and the alternator pulley.

How do you measure a pulley for an alternator?

The pulley ratio is the diameter of the crankshaft pulley divided by the diameter of the alternator pulley. Multiply that number times the engine RPM to get the alternator RPM. For example, a 6 inch crankshaft pulley and a 2 inch alternator pulley equals a pulley ratio of 3:1.

How can I make my pulley faster?

Pulley systems entail two pulley wheels on a shaft joined by a belt. These wheels are driver and driven pulleys. By changing the diameter of the pulley wheels, speed can be changed. A smaller pulley turning a larger pulley results in the larger one moving more slowly but with more shaft power.

What sound does a bad alternator pulley make?

Growling or Whining Noise If the pulley is not in correct alignment with the belt, or if the bearings are won out, the alternator will make a growling noise. Be sure to perform a visual preventative check of the belt for cracking, excessive wear and other age-related issues.

Do alternator pulleys go bad?

An alternator pulley is not so simple anymore. If the internal clutch mechanism is bad, the pulley may slip and fail to drive the alternator, or it may remain locked all the time – increasing noise, vibration and stress on the belt drive system.

What causes alternator pulley to go bad?

Pulleys do go bad because the grease in the pulley bearing dries out, the ball bearings and bearing races get pitted and then the pulley becomes noisy. Sometimes, the pulley will actually seize. However, it will be EASILY evident if a pulley bearing is bad. So, all you need to do is have them PROVE the failure to you.

What causes alternator to lock up?

Alternators have moving parts, get dirty and are subject to stress from heat and cold. As a result, the internal parts gradually wear out. One of the most common failures is bearing failure. When the bearings fail, the rotor will not spin efficiently and can eventually seize.

When should I replace pulleys?

An idler pulley is expected to wear over time, and eventually the pulley will fail. Replacement intervals for idler pulleys vary, but are usually within the 50,000 to 100,000 mile range. Replacement often coincides with expected serpentine/accessory belt replacement periods.

Do you need clutch pulley on alternator?

The alternator pulley is also vital to absorbing crankshaft pulsations from hitting the alternator. A failed pulley will no longer clutch properly. The action of slowing down the alternator forcefully puts a lot of extra stress on the accessory/serpentine belt system.

Should an alternator spin both ways?

Rule of thumb. If the engine rotates clockwise, which it does, then any pulley driven by the inside of the belt rotates clockwise, and any pulley driven by the backside of the belt turns counterclockwise, like the water pump.

How tight should an alternator pulley be?

Tighten the nut with an impact wrench until the lock washer is completely closed and the nut is tight (about 70 ft-lbs). Do not over tighten.