'12 AC Compressor or Clutch?

[CCS86]

Hi guys,


How likely is it that the AC compressor clutch only fails?


I was driving home yesterday slowly, AC was blowing cold. Then I heard kind of a steady "wooooooooooooooo" noise. I immediately turned off the stereo, still there. I thought it was something driveline, shifted into neutral, still there. After about 8 seconds it tapered and was gone.


At that point I noticed the AC was blowing warm. Back in my driveway, nothing was leaking out, and no condensate was dripping. I came back to it this morning, had it idling, then kicked on the AC. I watched the compressor, and while the outer portion was spinning (marked green), the inner section (red) appeared to be rotating very slow. I thought it might be an optical illusion, but over the next 30 seconds or so, it slowed to a stop.


I'm trying to decide how likely it is to just be a clutch problem, vs the compressor failing and overcoming the clutch. The connector is still intact.


Thoughts?

 

[mastwolf]

Clutch, does it look kinda melted?

It sounds like the clutch, you can get a new clutch for it, and swap it while its on the car, did mine about 20k miles ago.

 

[CCS86]

I hope it's the clutch!

When I stopped right after it went out, nothing smelled out of the ordinary. No burnt clutch or rubber smell.

I'm not really sure what the clutch mechanism looks like in these, so I don't know if there should ever be relative motion between the parts I marked red and green. The fact that toggling the AC causes the green part to rotate or stop suggests that the clutch is still working. But maybe something that is press fit sheared apart between the compressor shaft and outer pulley.

 

[mastwolf]

I hope it's the clutch!

When I stopped right after it went out, nothing smelled out of the ordinary. No burnt clutch or rubber smell.

I'm not really sure what the clutch mechanism looks like in these, so I don't know if there should ever be relative motion between the parts I marked red and green. The fact that toggling the AC causes the green part to rotate or stop suggests that the clutch is still working. But maybe something that is press fit sheared apart between the compressor shaft and outer pulley.

The part that connects to the compressor is probably melted same thing happend to me. Grab a clutch and throw it on there. You dont have to pull the compressor or the belt/pulley just un bolt the clutch and slap the new one on.

 

[CCS86]

The part that connects to the compressor is probably melted same thing happend to me. Grab a clutch and throw it on there. You dont have to pull the compressor or the belt/pulley just un bolt the clutch and slap the new one on.

Thanks mastwolf. Were you able to find the clutch alone? It looks like Ford sells it with a pulley: http://parts.lakelandford.com/a/For...R--LINES-AIR-CONDITIONER--HEATER/JC10147.html

 

[Dig Race]

Parts geek has new compressor with clutch for $195 free shipping. I thought mine was clutch too but the seal behind it went then clutch came apart.

 

[CCS86]

Okay, finally got back in town and yanked the inner clutch portion. It is for sure toast.

I'm wondering whether replacing that alone would be a bad idea. I have the whole clutch pulley assembly, but obviously replacing everything will take longer.

 

[CCS86]

 

[CCS86]

I popped the new clutch disk in for a test. It seems to work well. Everything is locked together with the AC running, and it blows cold. Sweet!

When I turn off the AC, it mostly disengages, but not completely. The clutch very slowly rotates in little pulses. Only a few RPM I'd say.

Is that a sign of a worn out pulley, or it needing shims?

 

[CCS86]

The service manual says that each individual component can be replaced as needed. So long as there is not excessive grooving/wear in the other components.

It is pretty clear on my system, that eventually the outer portion of the clutch shifted and closed the required air gap. With it now rubbing against the pulley and generating additional heat, the failure is no surprise.

Can anyone explain to me why our pulley's band of friction material is flush with the surrounding metal faces, and the mating face of the clutch, has no raised section?

It seems that by just cleaning it up, and shimming the new clutch for air gap has everything functioning well again.

 

[greenscobie86]

Good info here, thanks!

 

[SHIFTYBUSINESS]

Yeah I agree good info. Just curious how many miles were on it before it let go?

 

[CCS86]

33k

 

[JDos1]

Had the exact same issue today. About a 4-6 second "woooo" and then warm air. Did you end up having to shim it? If so what did you use to shim it?

137K on mine and first AC related issue I've had besides a sticking blend door that cycling the functions fixed.

 

[CCS86]

Yeah, I used all 3 included shims to begin with (0.030", 0.020", 0.004"). I ended up removing the 0.020" shim to get the air gap in spec.

Has been working just fine since, but I am still thinking about replacing the pulley as well. Trying to get some information on how tight the bearing to shaft fit is, and the best way to install a new belt (assuming I just cut the old one off)

 

[JDos1]

The FSM procedure for belt replacement looks super easy. Link attached. Just zip tie the belt to the crank pulley and walk it on.

http://iihs.net/fsm/?dir=865&viewfile=Air Conditioning (AC) Compressor Belt - 3.7L and 5.0L.pdf

How much of a PITA was the clutch removal/install? Reading through the FSM it says it requires special tools and such. Did you require anything other than basic hand tools?

 

[CCS86]

Hmm, link doesn't work, but I can dig up that page.

Removing the clutch only is a piece of cake. You really just need a 10mm socket. If you take out the two coolant reservoir bolts and move it to the side, there is actually a decent amount of room to work.

It's just a pain to restrain the clutch while breaking the bolt loose; especially when the clutch is smoked. I had a little adjustable pin wrench that happened to fit nicely in some holes in the clutch. You can find a simple clutch holder tool on Amazon for about $12. Or you could just use an impact / smack your rachet handle with a hammer, to break it loose. Make sure to use blue loctite when you reassemble.

 

[JDos1]

Thanks man!

 

[JDos1]

Replaced all three items tonight. Cake.

My clutch bolt was barely torqued. Took it off with the belt still on, then removed the snap ring and slid the pulley and belt off (no need to cut). Did require using a pry bar and some slight manipulating being careful not to damage anything on the block/heads. Removed serpentine (easy peasy). Removed field coil. Installed new field coil. Installed new pulley. Gapped clutch. Walked ac belt back on using FSM procedure (stupid easy). Installed new serpentine. Reattached degas bottle and CAI tube. Done. Cold air once again.