I'm now replacing the belts on my stock 90 GTU, and one of the pulleys was making a loud squeaking noise. I'm suspecting it's the alternator pulley but I wouldn't mind replacing the idler and tensioner pulleys as well. What would you guys recommend as a replacement?

 

You can buy both the PS and AC idler pulleys from Rockauto for about $15-20 each. They are DAYCO 89039 and DAYCO 89036, which are a lot cheaper than Mazda idler pulleys. I once had a problem with the PS idler making a screeching noise above 3k rpm. These idler pulleys use a sealed ball bearing, which has a limited lifespan. You might want to also checkout your power steering pump bearings and fan clutch.

 

Thanks I'll pick those up. I was looking at the FSM though and it looks like I'm missing the AC adjusting bolt when compared to what I have. It's supposed to be right near the PS adjusting bolt right? I guess I can't even change that belt until I get the adjusting bolt.

 

Do you even have AC?

No adjusting bolt, no AC idler pulley, and as far as I can see no compressor..

 

I thought I did, I've had the air blowing semi-cold while running before. I'll really feel like an idiot if I don't but a relief that I'm not actually missing anything.

 

I installed the new pulley but, on the stock pulley there is an indent on the backside for the dust shield to sit snug in, and there is no indent on the DAYCO one. It doesn't seem to sit snug and it doesn't spin freely when bolted up. Did you run into the same problem? Could I go without the dust shield?