AC clutch slinging oil

[Hypoid]

I fixed one leak in time for another to start. :jester:

1990 Limited, power everything.

I had a nice, long, fast highway trip yesterday. Today I checked the fluids and found oil/grease in line with the AC clutch. With the AC off, there is some noise that could be the idler pulley bearing. When I turn the AC on, there is much more noise, and it pulls the engine idle down.

Obviously, the AC pump is shot, just not seized...yet. My question is, can I disconnect the power to the clutch and not worry about those clutch bearings?

 

[WB9YZU]

If the bearing is bad, disconnecting the clutch power won't fix it.
Take the clutch apart and replace the idler bearing.

_Ron

 

[Hypoid]

You are saying the clutch bearing is bad because the clutch pulley is slinging oil?

 

[WB9YZU]

What I'm saying is that I read that you have diagnosed your AC pump as having a bad pulley bearing.

And...

The pulley on the AC unit is serviceable without having to replace the AC unit.

You could also use a AC bypass pulley if you want,
But if the AC is charged, and normally works when the clutch does,
I'd replace the bearing inside the pulley and call it "good".

~Ron

 

[WB9YZU]

Forgive my 2nd response. I was on a phone earlier.

The AC clutch is not part of the Compressor, it is a bolt on. It consists of a electro magnet, a pulley which covers the magnet, and a clutch plate which is keyed to the end of the Compressor shaft.

The pulley bearing rides on the nose of the Compressor and is held there with a e-clip. When the pulley bearing dies, the grease will leak out the seal, the pulley will growl for a while, then tilt. The Clutch will operate erratically, and the clutch plate will be the only thing holding your belt on.

So before that happens. Remove the Clutch plate (nut). Be sure to collect the shims and store them in a baggy for later. Remove the E-Clip holding the bearing on, and remove the pulley from the nose of the Compressor. (In advanced stages the pulley will fall off, along with any bearings left, and you will simply need to remove the race from the compressor nose). Once you get the pulley off, the bearing on the early models is held to the pulley with another e-clip. Remove it and replace the bearing.

HTH

~Ron

 

[md21722]

The clutch bearing always spins. If it seizes it will likely take your whole serpentine belt with it and leave you stranded. The cost on new clutches is comparable to the cost of the compressor, but if you're trying to save your R12 then it may be worth just changing the clutch. Or the clutch bearing as WB9YZU suggests.

The A/C compressor has a keyed shaft that the clutch plate goes on. The wiring activates an electromagnet which draws the clutch plate to the spinning clutch pulley. Once activated the compressor shaft turns.

 

[Hypoid]

Thanks for the follow up!

When the pulley bearing dies, the grease will leak out the seal, the pulley will growl for a while, then tilt.

That is what I was worried about, just did not know if the pump itself could leak from the front. This thing gets changed out today!

I did poke around some with a stethoscope. Whatever I am hearing is not the AC pulley bearing. The idler pulley makes enough noise that I'll replace it, but, I have yet to isolate the noisy bearing.

 

[Hypoid]

Just a quick follow up, both the AC clutch bearings, and the idler bearing were toast.

Lessons:
A) You can have more than one problem at a given time.
B) Sometimes, you have to take stuff apart to get a complete diagnosis. I did not have to replace any other parts.
C) The Harbor Freight Mechanics Stethoscope is the worst I have encountered.
D) The factory shoulder washer will work with the autostoned idler pulley, but not their AC Delete Pulley. The shoulder washer that comes with the autostoned Idler Pulley, will work with their AC Delete Pulley.