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. If the charging system warning indicator is on, the OAD may be the culprit, not necessarily the alternator.
What does an alternator decoupler do?
An OVERRUNNING ALTERNATOR DECOUPLERTM pulley
helps “synchronize” the belt drive system for improved engine efficiency, reduced Noise/Vibration/Harshness (NVH) and increased component life
. When an engine accelerates, the alternator's mass creates resistance against the belt.
How much does it cost to fix 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.
What is alternator decoupler pulley?
How do you fix a seized alternator pulley?
What happens if alternator pulley breaks?
If the tensioner or pulleys are worn or damaged,
they could cause a loose serpentine belt that might just fall off instead of breaking
. Poor serpentine belt tension can affect the engine accessories, and the power steering pump or alternator won't function properly.
What causes an alternator pulley to break?
A worn overrunning alternator pulley
often blocks and performs like a solid pulley. This will cause the belt to slip across the pulley surface during belt and alternator speed fluctuations.
Do alternator pulleys go bad?
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. Another type of special pulley is an Overrunning Alternator Decoupler (OAD).
How long does it take to replace an alternator pulley?
If you decide to change it yourself at home without much experience, it should take you around
3-4 hours
, depending on your vehicle's make and model.
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 much does pulley repair cost?
The cost to replace the idler pulley of your driver belt will usually be somewhere
between $80 and $200
. The cost for the new part should only be anywhere from $40 to $90, while the cost of the labor will be anywhere from $40 to $110. These prices do not include added taxes and fees charged by the auto shop.
What is a decoupler?
(diːˈkʌplə) noun.
a person or device that disconnects parts that are joined
.
How does an alternator overrun pulley work?
The overrunning alternator pulley is a further development of the fixed belt pulley on the alternator. Thanks to its overrunning clutch, it damps the vibrations which are generated by cyclic irregularities in the crankshaft and also enables the engine speed to be reduced rapidly in the event of sudden load changes.
How do you change a clutch pulley on a alternator?
How does alternator clutch pulley work?
This is where the clutched alternator pulley comes in – just like the bike, the alternator can “free-wheel” at the higher speed, spinning down gradually until the alternator speed matches the engine speed, at which point the pulley will engage again, just like your bike.
How does OAD pulley work?
Unlike an overrunning alternator pulley, an OAD pulley features a sophisticated internal spring and clutch system that
absorbs the force generated by belt accelerations and tension reversals
. An OAD pulley also allows the alternator to “free-wheel” or “overrun” when the belt suddenly decelerates.
Why would an alternator seized?
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.
What causes seized alternator?
One of the most common failures is
bearing failure
. The needle bearings that allow the rotor to spin freely inside the stator can break down from dirt and heat. When the bearings fail, the rotor will not spin efficiently and can eventually seize. Usually an alternator with bearings failure makes a loud grinding noise.
Can you repair alternator?
They can even leak which causes the battery to drain.
Repairing an alternator is a job for an auto electrician as it requires a particular set of skills
. Another option, if replacing your alternator is too costly, is to fit a refurbished or rebuilt one.
