[z28barnett]

have a bad bearing in the A/C pulley. The system works fine but has a wine that sounds like a blower or a gear drive cam.

The clutch is not dragging and the sound is roughly halfed when I turn on the A/C and at its worst when it is off. My thought is the bearing in the pulley spins all of the time and with the clutch pulled in it side loads the bearing to quite it down some. I can hear the noise when turning the pulley by hand.

I have looked up the procedure in the GM shop manual. The clutch plate has to be pulled with a special tool. Then another tool is used to lock into the center of the pulley and pull the pulley off of the compressor shaft.

They list another set of tools to install the bearing and stake it in place and finally another tool to reinstall the pulley on the compressor.

They say that this can be done on the car without opening the A/C system.

Prices for the parts:

Bearing: $20.00

Tools: Not sure

Compressor with shippping: (New GM) $350

Receiver Dryer: (New GM) $50

New Clutch Pulley assembly: $110

My questions:

1) Has anyone done this job, are the special tools needed and where do you get them?

2). Is a functional 90K miles A/C compressor ready to be replaced anyway?

3). What do you think would be the most cost effective way to proceed?

Thanks

Z28

[z28barnett]

I do this stuff all the time. Depending on how bad the pulley bearing is you might need more parts. Most ones I do need outer clutch and the pulley. Cars that have been driven to far might need a coil too. In cases where they really didnt pay attention it required compressor replacment where the bearing siezed and took the snout of the compressor out. Tools needed would be a ac clutch puller(Snap-on/equiv) depending on how stuck the pulley is it might slip off, need a little love tap or they do make a ac pulley puller. Its not that bad for a DIY if the compressor can stay on car.

One question is that you say the noise goes changes once the ac is turned on? Does it feel like the the clutch is dragging any bit. I've had alot of the Gm clutch have a noise( metal Scraping type noise) when the ac clutch starts to become warped and drag on the pulley which creates alot of heat!!. But when you turn the ac on it goes away. If you catch it soon enough and it the noise I think it is, you could just be able to do the ac clutch, anything else its going to need both. Let me know if you need anything else. John

Thanks for the post.

I with the engine shut off and the A/C off I looked at the front clutch plate from the bottom. I could see daylight all of the way around between it and the front face of the pulley.

I assume that the coil would pull back and close the gap to engage the compressor.

I felt very little drag when I spun the pulley but it felt somewhat rough and I head a faint grinding scraping noise.

With the engine running at idle the sound is very noticable, when I turn the A/C on, there is a pause and then a click and the noise drops by about half, but it is still there. The click is the clutch pulling in, and the noise drops because the bearing gets side loaded by the force from the clutch. That is my theory. I also ran the engine with the belt off and there was no noise, so unless I have two problems like the P/S pump and the A/C, I think the A/C is the problem.

I hope I have answered your questions.

I am concerned about getting the pulley off, due to rust. Everything has been siezed when I worked on the suspension.

Another concern I have is getting the pulley back on. The installer I have seen in drawings is kinda a bar with hooks and a center screw. The hooks go behind the ears of the compressor and the center screw pushes the pulley back on. I haven't seen those for sale around here. Pullers could be anything if you are just going to trash the compressor pulley.

The last time I had a problem with an A/C pulley it was easy to spot, little bits of bright metal flying out of the clutch.

This is a little more tricky.

Kudo's on the one lap events, I think that would be a great experience.

Z28