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It's likely all about the free wheeling aspects. Saves fuel.

What vehicle produced today doesn't have a decoupler alternator pulley? I guess the alternator creates the biggest bump in the serpentine belt and is frequent as well.
 

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fix it if you can
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Why AC Compressors, Water Pumps, Power Steering Pumps etc are not equipped with Decouple Pulley?

Alternator last longer?

First thing to fail is the alternator pulley, many people replaces a otherwise good alternator just because the failed pulley.
A/C compressor has a clutch pulley (will slip under sudden load change
water and PS pumps do not have the inertia of the alternator rotor (and operate at lower rpms - larger pulleys)
Some new vehicles have electric PS pumps / power assists, but that's a topic for another thread.

IDK if alt will last longer, but the belt drive components are stressed less with ADP.
If people replace perfectly good alternators, those returned as core are re-sold so they do last longer :) (and someone does 'good business')
 

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A/C compressor has a clutch pulley (will slip under sudden load change
water and PS pumps do not have the inertia of the alternator rotor (and operate at lower rpms - larger pulleys)
Some new vehicles have electric PS pumps / power assists, but that's a topic for another thread.

IDK if alt will last longer, but the belt drive components are stressed less with ADP.
If people replace perfectly good alternators, those returned as core are re-sold so they do last longer :) (and someone does 'good business')
A good AC clutch should not slip, not at all.
 

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My experience is that the decouplar pulley outlasts the alternator.
 

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Decoupler pulley's function is to save wear on the tensioner. When the engine revs up and suddenly slows down with the upshift of the transmission, a regular pulley will continue to spin and pull the belt, jerking the tensioner. If the rotor mass is freewheeling during that shift, the decoupler pulley slows down with the belt and doesn't tug the belt or the tensioner. That's the best I can describe it from the video I saw on the subject here a few years ago.
 

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My experience is that the decouplar pulley outlasts the alternator.
The only experience I have is with my 2006 DGC.

Decoupler pulley first made an ugly noise, for some time. Then it froze solid and problem solved, never replaced it and never noticed any strange noise or weird serpentine belt vibration, wear, noise etc.

When you turn engine off, the alternator's stator should stay spinning for a second or so, but sincerely I never pay attention to it, so I don't know if it is true or not.
 

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Levy, AC clutch slipping is during engagement, not while running/engaged. It basically has to slip a little until the two plates are turning at the same speed. It happens quickly, but there is some slipping.

Of note, in 1966, when I was stationed in New Orleans, I was driving my friends brand new air conditioned VW Beetle, and when the AC compressor engaged, you'd feel the car jerk. Everything was air conditioned in New Orleans, even my 1964 Chrysler Convertible! We'd come off the flight line, after working inside airplanes, and we'd basically ring out our shirts. From what I understand, Canada didn't get AC till 1985!
 

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Levy, AC clutch slipping is during engagement.

Of note, in 1966, when I was stationed in New Orleans, I was driving my friends brand new air conditioned VW Beetle, and when the AC compressor engaged, you'd feel the car jerk. Everything was air conditioned in New Orleans, even my 1964 Chrysler Convertible! We'd come off the flight line, after working inside airplanes, and we'd basically ring out our shirts. From what I understand, Canada didn't get AC till 1985!
I know, but is not what atoman meant.

VW bug engines of that era were not meant to have AC system. Probably had a 1200 CC engine and aftermarket AC. Even late 70's VW Bug with a 1600 CC engines had problems running an AC.
 

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AC on a 1966 Volkswagen Beetle ............ those things didn't even have a gas gauge. :)
 

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A good AC clutch should not slip, not at all.
Levy, AC clutch slipping is during engagement, not while running/engaged. It basically has to slip a little until the two plates are turning at the same speed. It happens quickly, but there is some slipping.
I know, but is not what atoman meant.
Mind reading is an art, and artists must have their genius...

A/C clutch is nothing more than two steel disks (plates) pulled against each-other with magnetic force.
Any time the impulse energy of load change exceeds the friction of the clutch, it will slip (physics 101).

Under normal operation the clutch is used to control the compressor, it slips when applied and released.
Compressor does not have notable inertia - it takes energy to pump refrigerant and there's no flywheel on the compressor so under sudden deceleration of the belt it should not slip. Acceleration of the belt is not instantaneous enough to cause slippage of engaged clutch because pump driven component mass is small and gas (vs. liquid) will readily absorb the 'shock'...

Make no mistake, should compressor seize while engaged the clutch will slip.

LEVY, any clutch that "does not slip at all" by definition can't be good :)
 

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Any time the impulse energy of load change exceeds the friction of the clutch, it will slip (physics 101).

Make no mistake, should compressor seize while engaged the clutch will slip.

LEVY, any clutch that "does not slip at all" by definition can't be good :)
Guess what?

I have seen engines that people thought were seized and it was nothing but a seized AC compressor.

After removing the accessory belt engine would crank and start.
 

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Guess what?

I have seen engines that people thought were seized and it was nothing but a seized AC compressor.

After removing the accessory belt engine would crank and start.
Obviously, these cases did not have good clutch (it should not stay engaged while starting engine).
It's fairly common for the clutch to 'weld' together when it overheats while slipping on a seized compressor...
 

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Good discussion, and I'm glad I started it. Jeepman, as I said, Canada didn't get AC till 1985, and TV till 1986! In NYC, I remember them delivering our first TV in 1949, when I was three. I remember watching a lot of wrestling, and later, news of the Korean war.
 

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Don't know about air conditioning, we had vent windows, but TVs were around, showing lots of snow, in the 1950s, maybe 1940s. Outside antennas, rabbit ears and all that stuff. My Grandfather had a new 1950s Sylvania Halo Light TV. His neighbors use to gather round to watch it. He owned a General Store too, so there were lots of neighbors and smoke.
I can remember watching Have Gun Will Travel and other westerns on a neighbor's TV on Friday nights.
In the 1950s, some vehicles had record players. History of obsolete car audio, part 2: Record players | Hagerty Articles
 

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You missed my point that I don't want to dink with it. I just want to R&R it and be done.

Problem is, I don't see any listed on Rock Auto, Napa, Advance, Auto Zone, O'Reilly's that don't have it without the OAD on the end.
Interesting here....
Esteemed member CMNTMXR57 is looking for a solid pulley alternator for his broke down smokin, squeaky 'End of Life' work van. He seems to be a mechanic of sorts and with this ole heap he is just looking for something he can slap on there until "the end".

A few offers and suggestions were made and rejected.
He just wants a quick fix, something he doesn't have to 'dink with', just a rapid R&R. Doesn't even want to change a pulley, a complete alternator assembly pre-built with a solid pulley, that is what he is searching for.

**(I assume that CMNTMXLMNOP57 is a he, awfully sexist of me to assume that more likely that a car aficionado is likely a he, sorry ladies... )

And there in causes my confusion, why, if you are going to slap in a pre-built complete alternator assembly in, wouldn't you put in one with an OAD? The advantages are there and they are readily available.

I understand you got a bum one from somewhere, I get that you now HAVE TO CHANGE another because of that crap new fangled funk pulley, but it's premature failure was likely a fluke.
 

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I had one of the first remote controlled TV's.

It was a Zenith with a two button remote (wireless), no batteries required :oops:

I had to leave it behind during a moving. :(

Anyone else here had one of those?
 

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CMNTMXLMNOP57, sometimes the the rebuilt alternators don't include a new decoupler pulley, as the cheaper rebuilds don't include parts that are not worn out or broken.

Levy, my cousin had one of those remotes, and I think they used tuning forks.

See link: Robert Adler - Wikipedia
 

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What's funny is that years ago when aftermarket alternators for these vans were being sold, most had a regular pulley. Customers complained and the aftermarket listened, and now the alternators are sold with the AOD pulley on them.

Maybe you really just need a time machine? :ROFLMAO:
 
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