Squeaking pulley? Don't replace it. Regrease it! *pics*
Here's the pulley itself. The bolt is a torx t50. I couldn't find that size listed in any of the searches I tried here or elsewhere, so hopefully it will help someone out. The rest of the pulleys use a 15mm bolt; not really sure why GM chose to use a torx bolt on the a/c idler pulley.

The bearing seal comes off pretty easily. Just pry on the inside with a small flathead screwdriver and it'll pop right out.

Here are the actual bearings. As you can see, they're completely dry and when it rains or gets humid out, moisture gets in and you get your squeaks and squeals. After a while, that condition becomes permanent until the bearings are repacked or the pulley replaced.

Repacking the bearings can be a messy job, but if you use enough grease the pulley will stay quiet even longer than it did when it was new out of the box. They use minimal grease from the factory which is why even the replacements start making noise after a year or two.
Just get some grease on your finger and push it in, working your way around. When you turn the bearing, and grease begins to weep out of the back side of the bearing race, you've got enough in there.

Now you can reassemble the pulley. The seals slip right back into place, just push it down in one spot until it pops down into the groove, then work your way around until it's completely seated. Once you have the seals on both sides, rotate the bearing several times and wipe off any excess grease that may ooze out from under the seals; don't want that getting on your belt or splattering around on your motor.
Here's the finished product ready to be reinstalled. This will work to quiet down the other idler pulley and your tensioner pulleys as well. A lot cheaper than replacing them, and it only takes a few minutes.
Trending Topics
The Best V8 Stories One Small Block at Time
Here's a question: what's the easiest way to determine which pulley is making noise? I get a little bit of noise sometimes that sounds like a pulley.
The a/c tensioner pulley you can get from Napa, but when I replaced mine I ordered it from GMPD.








