AC Compressor Bearing Failure?

frankiep1 · 12-01-2013, 07:36 AM

My son's 85.5 started getting a pretty loud harmonic type of a hum/growl at about 3K RPMS. No sound at idle but would start after revving and stop again after dropping back to idle. After removing belt to see if Alternator or AC Compressor was causing it, it went away. Put belt back on and further diagnostics proved it to be the AC. It failed with and without AC clutch engaged. I loosened the belt a bit to remove some tension and got it to a point where it only now makes the noise with the AC clutch engaged. Sure seems like a bad bearing to me. Is this something that's repairable or do I need a new compressor?

mattdavis11 · 12-01-2013, 08:06 AM

You don't need a new compressor. I wouldn't let anyone touch it for a rebuild either. It's pretty easy to change the bearing. If you need one, I have one. I would also check the rubber damper on the front of the compressor for cracking, deterioration.

frankiep1 · 12-01-2013, 08:37 AM

Thanks Matt. I've been looking at other posts and it looks like I should be able to find a bearing relatively easily. Any thoughts on doing it in the car so I don't have to disconnect the lines and recharge? I'm hoping I can remove the mounting bolts so I can move it a little bit but don't know if that will provide enough room. Also, any help on "how to" replace the bearing would be appreciated. I'm pretty sure I can figure it out by looking at it and a little more reading but since you said it's easy I assume you have experience that might help me.

Much appreciated!

v2rocket_aka944 · 12-01-2013, 09:09 AM

Auto zone has a clutch removal tool for rent. Tell them it's for a Ford. It has threads on the outside and inside and a bolt with a point to pull the clutch off. The whole church and bearing assembly will come off without breaking the seal if you're careful

kuehl · kuehl's Garage

You can remove the entire clutch assembly with common tools unless someone has buggered up the compressor's nose where the pulley bearing's inner race rides on.
You'll need a press to push out the bearing and press in the new one, and you'll have to be cautious not to distort the pulley.

But before you proceed you'll want to consider how many miles are on the compressor, it is original, or a rebuilt at one time, and whether the internals (piston bores, piston and wobble plate) are in good condition before you spin your wheels.

frankiep1 · 12-01-2013, 05:57 PM

Thanks Kuel. I did a conversion on the system with a kit from Griffiths about 12 yrs (50K miles) ago when it was my daily driver, so hopefully the compressor has some good miles left on it. I'm going to give it a try as soon as I can make time. My son's driving it now and the cool weather right now means this can wait a bit until after holiday stuff is done.

kuehl · kuehl's Garage

Unplug the wire at the compressor clutch, and remember you won't have an effective defrost (no dry air).

mattdavis11 · 12-02-2013, 05:14 AM

8 or 10mm socket, snap ring pliers, possibly a 3 jaw puller, two blocks of wood (2x4's are good), a hammer (a mallet is better) and a big socket. I've never used a press to remove and install nose bearings.

The first thing I would do (if you don't have an impact gun) when removing the clutch assembly on the car, is remove the 8 or 10mm bolt before you unbolt the compressor. Hold the clutch and give it a whack.

Once the assembly is off, use the two blocks of wood, a large socket, a hammer, and drive out the old bearing, then pound in the new one utilizing the wood.

Let me know if you have any questions.