Why do alternators have a clutch pulley? As opposed to traditional solid pulleys, they allow the alternator to “free-wheel” or “overrun” every time the engine decelerates and, at the same time, dampen vibrations at the alternator. They come in two types: one-way clutches (OWCs) and overrunning alternator decouplers (OADs).
What does a pulley on an alternator do?
The clutch pulley on an alternator allows the belt to turn freely in its own speed in one direction when the engine suddenly slows down. A properly functioning overrunning alternator pulley results in a smooth and quick running accessory belt system.
How to replace an alternator pulley?
How-To: Replace an Alternator
- Disconnect the Battery. First and most importantly: disconnect the battery. ...
- Disconnect the Wires. Now that the battery is out of the way disconnect the wire or wires from the back of the alternator.
- Remove the Belt From the Pulley. ...
- Remove Bolts. ...
- Halfway There. ...
- Examine the Replacement. ...
- Reverse the Removal Steps. ...
How do you remove the pulley on an alternator?
- Place a suitable sized 1/2-inch drive impact socket onto the alternator pulley bearing retaining nut.
- Test the gun to make sure it is rotating counterclockwise.
- Attach the anvil of the gun to the square drive of the socket.
- Use a pair of channel locks to hold the pulley bearing stationary.
- Remove the pulley bearing.
Why is the clutched alternator pulley?
Why do alternators have clutch pulleys? The clutch pulley allows the alternator's heavy rotor to overrun, absorbing shock, each time the alternator cycles on and off (about 3 times per second). The result is smoother idle, no belt chirp, increased life of alternator, power steering pump, water pump, sepentine belt and automatic belt tensioner.
How to think about clutches alternator pulleys?
The most simple way to think about clutches alternator pulleys is to imagine riding a bike – a normal bike not a fixed wheel bike . You pedal to build up speed, but, when you stop pedaling the bike keeps moving even though you’ve stopped pushing the pedals.
How to tell if a serpentine belt is jumping?
If the pulley is jumping up and down shows that the tension on the belt is changing with crankshaft pulsations we talked about earlier.
How to test alternator pulley?
You’ll need to start by taking the serpentine belt off so that you can rotate the pulley independently of the engine. Once the belt is off, you’ll need to find a way to counter-hold the alternator internals.
How to tell if alternator pulley is clutched?
Clutched pulleys will have a cap while un-clutched pulleys typically will not. On the alternator above the end of the pulley is covered by a black cap, thus it is a clutched-type pulley.
What does it mean when the serpentine belt tensioner fails?
First, if your serpentine belt tensioner has failed, it is likely that the alternator pulley is faulty as well. Typically the failed pulley is the cause of the tensioner failure.
What happens if a pulley fails?
What happens if that pulley has failed? 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. That violent change in momentum and speed is transferred from the pulley on the crankshaft, through the serpentine belt, around the tensioner and eventually makes it to the alternator. Over thousands of miles all that extra stress will cause the tensioner to fail, the harmonic balancer to become looser and might cause the serpentine belt to stretch or snap. It will also add extra side load to the A/C compressor clutch, which might also experience early failure.
What is a one way pulley?
Most modern vehicles have clutched or so called one-way or decoupler pulleys. Proper operation of these pulleys is vital to alternator health and the health of other components, especially the serpentine belt tensioner.
How to fix Alternator pulley not spinning?
The unspinning alternator or a seized alternator causes various problems to the engine. It sometimes agitates the owner and the first thing that comes to mind is to replace the seized alternator pulley. But knowing the correct way of fixing an alternator pulley will solve the problem as well as save that money as an alternator pulley in the market can cost up to $200.
What is alternator overrun pulley?
The alternator overrun pulley or one way clutch turns only one way clockwise or anticlockwise and the other way is locked. It allows the alternator to free turn when the engine slows down or decelerates and decouples that mass away from the engine so it is not creating any vibration in the belt drive system.
What is the purpose of a clutch pulley on an alternator?
The clutch pulley on an alternator allows the belt to turn freely in its own speed in one direction when the engine suddenly slows down.
How to remove alternator clutch pulley?
Now if the pulley nut has the standard right hand threads rotate in an anticlockwise direction for removal if not then rotate clockwise with a ½ drive impact wrench or 15/16 socket while keeping your eyes at the alternator.
How do you know if your alternator pulley is bad?
There are few signs of the alternator pulley when there is a problem in it. The first is excessive tensioner movement. If a short buzzing of 1 to 5 seconds is heard after shutting down the engine it signals that the alternator might have to be replaced. There can also be a chirping sound caused by the worn out bearing when the engine is starting or shutting down.
Should the alternator pulley move freely?
Yes, the alternator pulley should move freely in the overrun direction and come to a stop in the drive direction. It helps the alternator to shut off right away after the engine is shut. Its overrun feature removes the belt chirp noises during engine shutdown.
How do you Unseize an alternator pulley?
It is actually a very simple task to unseize an alternator pulley. Put a bit of motor oil, transmission fluid or even old motor oil will work. Then put a socket in the breaker bar and move the seized pulley back and forth. The first movement can get difficult but once done it will start moving like a brand new one.
How many times does an alt pulley sieze?
If the serp belt tensioner on an alh is rattling, bouncing, and the dampener is leaking, 9/10 times the alt pulley is siezed.
What happens when you stop peddling a bike?
It's like riding a bike; when you stop peddling the bike will coast along instead of coming to an abrupt stop. The rotor inside the alternator continues to spin faster than the engine rpm when you let up on the accelerator. At least that is what I observed when I tested mine with the serp. belt removed. L.
Does the alternator make the diesel engine drop rpms faster?
I suspect it is probably as much or more a factor of how heavy the spinning mass of the alternator is than it is the diesel engine dropping rpms faster.
What year was the B4?
That was the B5/5.5. The B4 was '96/'97.
Why does a diesel stop rotating when shut off?
Because of its high compression the diesel stops rotating in an instant when it's shut off. The clutch prevents damage to the belt/pulley/alternator by mitigating this shock.
Does a clutched pulley reduce voltage spikes?
I think the clutched pulley eliminates voltage spikes to a certain degree. It's like riding a bike; when you stop peddling the bike will coast along instead of coming to an abrupt stop. The rotor inside the alternator continues to spin faster than the engine rpm when you let up on the accelerator. At least that is what I observed when I tested mine with the serp. belt removed.
Does a diesel engine spin continuously?
All engines but diesel especially don't "spin" continuously. During the compression stroke the slow radically and during the combustion stroke the speed up radially. The weight of the alternator guts slowing and speeding like that make the tensioners rattle. The clutched pulley allows it to freewheel and keep spinning during the slowdown of the compression stroke, and avoids the tensioner rattle. Sometimes the one-way clutch fails where it doesn't freewheel and it makes the tensioner rattle.
WHAT IS A PULLEY? WHAT DOES A PULLEY DO?
Pulleys are simply a means of transferring power. In the automotive pulley and belt system the power generated by the engine is transferred from the engine crankshaft pulley to the belt and then from the belt to the pulleys attached to various accessories such as the Alternator, Power Steering Pump, Air Conditioning Compressor, Water Pump etc. In the early years of automobiles a narrow "V' shaped belt was used to drive the accessory pulleys with vehicles having as many as 3 separate belts. Most modern vehicles use only one belt to drive all the accessory pulleys. This is a wide belt that is flat on one side and has small "V" shaped ribs on the other side. Both the flat (smooth) side of the belt and the ribbed side can be used to drive pulleys. This belt is commonly referred to as a serpentine belt but also goes by many other names including Multi-V belt, Poly-V belt, Poly-Ribbed belt, Micro-V belt and others. Depending on the vehicle and engine the number of "ribs" made into the belt , which determines the width of the belt, varies from 5 to 8 with 6 being by far the most popular size or width. Alternator pulleys also come in various outer diameters.
How much does a pulley cost?
And just to bring the whole picture into focus the price of a standard solid steel pulley (which you would most likely never have to purchase) at retail is around $10.00 to $15.00 while the average price of a clutch or decoupler pulley (which if you will almost certainly have to purchase if your car is so equipped ) at retail is around $80.00 to $100.00..... Money makes the world go round folks.
How wide is an alternator pulley?
Depending on the vehicle and engine the number of "ribs" made into the belt , which determines the width of the belt, varies from 5 to 8 with 6 being by far the most popular size or width. Alternator pulleys also come in various outer diameters.
What is the reduction of the mechanical load on the entire belt system?
The reduction of the mechanical load (drag) on the entire belt system which reduces the vibration in the belt drive system and decreases belt tensioner motion.
What is a V belt?
In the early years of automobiles a narrow "V' shaped belt was used to drive the accessory pulleys with vehicles having as many as 3 separate belts. Most modern vehicles use only one belt to drive all the accessory pulleys. This is a wide belt that is flat on one side and has small "V" shaped ribs on the other side.
What is a serpentine belt?
Both the flat (smooth) side of the belt and the ribbed side can be used to drive pulleys. This belt is commonly referred to as a serpentine belt but also goes by many other names including Multi-V belt, Poly-V belt, Poly-Ribbed belt, Micro-V belt and others.
Does Metroplex have alternator pulleys?
Metroplex Alternator & Starter carries a full line of alternator pulleys for any application. Whether you need a conventional solid pulley. a clutch pulley or a decoupler pulley. We have them all. If you need an alternator pulley for your car, truck, boat, forklift, lawn mower, or tractor we have it. Since the alternator clutch pulley and alternator decoupler pulley require special tools for removal and installation we are happy to do the installation for you when you bring your alternator in off the car.
How many amps does a 2005 997 have?
Just found out today that the 2005 997 went to a 150 amp identical unit which is upgraded from the 120 amp unit.
Can you put a solid pulley on a manual transmission?
It is possible to install a solid pulley on cars with manual transmission without differences or issues, take note that solid pulleys needs metal rollers instead of plastic rollers. Solid pulleys gives too much wear on plastic rollers, you have to change them out for metal ones.
Do Boxsters have pulleys?
The early Boxsters all had a fixed pulley. http://www.renntech.org/forums/index.php?s...0&hl=pulley Are you replacing the alternator?
