Rattling sound from pulleys

Recently started hearing a loud rattling noise from the engine bay of my '99. Noticed this pulley (A/C compressor) was spinning erratically when I popped the hood. It almost seems as if the pulley itself is spinning fine but the outer "cover" for the pulley is slowly spinning as well. Took a pic to help explain

I'm hoping to pull the belts off when I get a chance to see how the pulley rotates without any pressure on it. Anyone else experience this?

 

The ac idler pulley bearing on my truck goes every 40 or 50k, makes a pretty horrible noise

 

Are you able to replace just the pulley/bearing or do you have to buy a whole new compressor every time?

 

My A/C idler bearing was going out. Replaced with a 6301 bearing (I think that was the right number) I ordered it online for under $5. Hardest part was removing the pulley and finding some snap ring pliers.

 

^yup 6301

 

Awesome, thanks! Will try to pull it off tonight.

 

If the noise the OP is talking about is coming from the pulley he has circled, that is not the idler pulley. The idler pulley is the smaller on on the right side of the photo, which is the 6301. The compressor bearing on the front of the compressor is a different one. OP, which bearing is making the noise? Typically it IS the idler bearing, and not the compressor bearing. Just want to make sure we are all talking about the same bearing. lol.

 

Lol yeah I assumed the op was mistaken and it was the idler pulley.. It's a lot more common and only costs like $10 to fix. Very well could be the compressor bearing though.

 

I've got to pull the belts off to spin the pulleys but I've suspected it's the compressor bearing. The outside of the pulley (which I believe is part of the clutch) is slowly spinning clockwise, leading me to believe the clutch could be bad.

 

The outside of the pulley that you are talking about is the clutch plate itself. If it is turning on its own a little, with the AC system disengaged it could be due to:

1. Worn bearing allowing belt driven pulley to "wiggle" and catch the clutch plate.
2. Clearance too small between clutch pulley and clutch plate.
3. Faulty clutch coil
4. Electrical problems in clutch circuit

Those are the only ones I can think of off the top of my head. But since you mentioned a noise, then a failed bearing is the most likely suspect.

 

Pulled the belt off this weekend. The pulley for the compressor has a ton of play in it so it seems the noise was coming from the pulley rattling against the clutch.

 

Did you fix it? If so what did you do?