As I can see from several threads that I searched, I am dealing with the dreaded belt chirp issue. It has been going on for quite a while now. I have changed belts several times, the last two times going to the Goodyear Gatorback belts for both accessory and a/c. Yesterday, it got particularly loud, so I started looking into the issue further. First off, I did try a little spray of belt conditioner on the accessory belt, and it went away. Guess I narrowed it to the accessory belt, as I never sprayed the a/c belt. Later in the day, it came back though. After searching online, I found several threads about the TSB addressing the issue, and found some that have said now that the idler pulley is not available from GM. After some looking around, I was able to find the alternator bracket and tensioner pulley mentioned in the TSB at Summit, along with Continental belts, who I guess took over the Gatorback design. Back in 2006, I got the GM vehicle inquiry paperwork, which does not show that the TSB was ever done. Don't know if that means it was never done, but it is not on the paperwork. Now to my questions. Since I sprayed the belt as a diagnostic, and it went away briefly, does that point to something else? If I get the alternator bracket at Summit, I have to get the pulley too? They list just the pulley, and also the whole tensioner assembly. The whole assembly shows it is for 98 to 02. Just the way I am, I want to replace the whole assembly since I will be taking stuff apart anyways. Will this part not be correct though if I install the new bracket, as far as alignment goes? Thanks for help or advice!

 

Based on your post above, you may be a bit confused about the TSB. The alternator bracket swap also calls for a new idler pulley, not a new tensioner or tensioner pulley. The main belt idler pulley attaches to this bracket, and you can't use the old pulley with the new bracket (or vice-versa) so you have to get both.

The updated alternator bracket was issued in mid-year 2000, so the pulley you need is the same as what came stock on any late '00-2002 model. The revised idler pulley part number was 12563326 per the original TSB (this number appears to still be valid and available, so I'm not sure why someone mentioned it was discontinued.) You have to get the new designed alternator bracket to make that pulley work. You do NOT have to replace the tensioner or tensioner pulley to complete the alternator bracket & idler pulley swap. However, the problem may in fact be your tensioner or tensioner pulley in the first place, so they may have to be replaced anyway.

On my 2002 (which came stock with the updated alternator bracket and revised idler pulley), I had to replace everything - both idlers (A/C and main), both tensioner assemblies (tensioners plus pullies), and both belts (with OEM belts, as the aftermarket Gates belts were just a bit longer and more prone to chirp) to finally get the noise to stop.

Lots of auto parts stores only seem to list one part number for the idler pulley, for 1998-02, and it always seems to be the older style pulley ('98-early '00) that they sell you. This has caused issues for folks who don't know about the updated bracket, because the older style pulley won't work correctly on the newer bracket that came stock on the later model cars. I remember a time when the revised pulley (part number listed above) was only available from GM and not any other source - not sure if that is still the case.

 

I see what I did there as far as the confusion goes, thanks for pointing that out. Guess I will start with the TSB parts, along with a new accessory tensioner, and see what happens. Have to clean the pulleys too. Only a couple a shots of that dressing made a mess. Won't use that stuff again!