Drive Belts Replaced ... AC Squealing!
 

Hi everyone! I hope I'm in the right place. (most of these posts are about ADVANCED things :o It makes me feel dumb lol)

The other day I had the alternator belt pop so that sort of forced a belt change. Just to be complete it was probably a good time to change the other drive belt.

It was a bit of a pain having to get at things from both the top and the bottom of the car but it got done. Everything seems great but... (always a but)

... whenever I turn on the AC and slow down to make a turn, during accelleration I hear a SQUEAL SQUEAL SQUEAL sound. It's gotta be from something with the belt but I'm not sure if that's because it's too loose or too tight.

I can't get it to squeal while it's standing, so to do trial and error means lifting the car and removing that plastic shield over and over again. Not fun. Any hints on which way (tighter/looser) I need to go?

squealing belt means loose belt...your not getting it with the AC off because there is no load whithout the compressor clutch engaged....go back and tighten it

yup.... with the car at idle run the AC full blast and have someone turn the steering wheel back and forth while you listen to the belt. With a 14mm socket and about 3 minutes you can have it snugged up just right.

"compressor clutch engaged"

Ahhhh.... I didn't even think about extra load. I just figured if it spun then it... well... nevermind. No need to show off "Duh". :)

Sounds good now, thanks guys!

My belts squeal with the a/c on - but it was the alt belt - just make sure you check tension on BOTH belts.

Yeah, just recently I had to redo it because that belt in particular loosened up. I think it was the other bolts that keep the alt locked in place weren't tight enough. The tight quarters makes getting at them kinda hard... plus this is the first car I've had without an automatic belt tensioner so I was kinda ¯\(º_O)/¯ about the whole thing.

It's good and tight and no noise coming out anymore, but I'm afraid it might be too tight. The spec is measured in mm and there's NO WAY I can fit anything in there to measure it. Anyone got any tips for that... (short of pulling the engine out ;) )

Can you push the belt 'a little' between the pulleys? If you can't - it is too tight and will wear your bearings faster. Loosen just until you can get some give on the belt.

The belt may stretch - mine did - so you may have to do it again in the future.

When it was squealing, if I push it a bit it would move maybe 3 or 4 cm, now with the same force it's like less than a cm. Unfortunately, it's by eye and muscle memory (pushing as hard as I did before). I wish I WISH I WISH I would have pushed on those belts when it was factory fresh so I'd have something to compare it to.

And it also helps that those long bolts were clean where they were set before, and the oxidation (??) around the rest of the bolt shows where it wasn't set so it gave some kind of feedback on overtighting.

Should be good now...

Is there a tool to measure belt tension??
Gates #91000?


Target

twist the belt on a span btwn pulleys, if you can twist it more than 90 degrees, it's too loose.

i installed a udp so unfortunately the "clean" part of the bolt doesnt apply to me anymore :(

i think you may have meant a 45 dagree angle 90 would be to loose i had this same problem no matter what i did it came back few days later so i takked to a mazda tek he told me the alt belt is thiner than most setups and go alittel father whithnthe tention havent had a problem yet

yea if it twists 90 its too loose.... mine twists 90 with a lot of effort but i have no squeel so it's fine. my alt belt only has 5 threads left on the tensioner bolt. but of course i have a udp so the puley is smaller so the bolt wil need to be threaded farther to get the tightness