THSCC Forums

So I did the Timing Belt on the Miata earlier this year and replaced the drive/acc belts at the same time.
Everything was fine until the weather got cold.

Belts squeal terribly on cold mornings. They quiet down after 2-3 minutes. I have tried tightening, I have tried loosening, I have tried yelling at them, nothing seems to work.
I am not really sure if it is one belt or both. I don't want to use any sort of belt dressing or band-aid type fix.
Anyone able/willing to give them a look?

They have to be pretty tight, tighter than you might think to keep them quiet. Also, check the grooves in the pulleys to make sure bits of old belt are not stuck in the bottom preventing the belts from seating and getting traction.

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92 Miata 1.9L naturally aspirated. SSM 21

Yep, you might be surprised how tight they have to be sometimes. The jeep I did the head on recently I had to tighten that thing a few times before it finally stayed quiet. There are actually ways to measure the tension on one but I think you need a special tool to measure the deflection.

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2017 Autocross Chief of Tech

2000 E Street Miata
2015 Focus SE EcoBoost 6 speed
2015 Fiesta ST (Wife's ride)
2012 Yamaha FZ1 sorta crotch rocket? All I know is 150HP and 487 lbs is fun!

http://www.amazon.com/Gates-91107-Belt- ... B000MUTAGS

Got me one of these. As others have send, getting a belt to spec will feel super tight.

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2013 Scion FR-S 10 Series - Solo Spec Coupe
Sold: 1999 Mazda Miata DD & CSP - viewtopic.php?f=25&t=15327

I probably need to tighten both up then.
That bolt on the back of the alternator is a pain.

I found that just using a box end wrench to loosen it by reaching under the alternator worked best. The filter is what is really the pain for me, lol.

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2017 Autocross Chief of Tech

2000 E Street Miata
2015 Focus SE EcoBoost 6 speed
2015 Fiesta ST (Wife's ride)
2012 Yamaha FZ1 sorta crotch rocket? All I know is 150HP and 487 lbs is fun!

I generally max the alternator tensioner out on my Miatas. Megasquirt driven cars tend to be a bit rougher on the alt belts though. They pretty much max out the alternator at startup vs ramping it up like the OEM ECU will. Make sure you loosen the mounting bolts on the top and bottom before adjusting the tensioning bolt or you'll shear it off.

I was worried before about over tightening and damaging a pulley. After everyone agreed they need to be really tight, I tightened both belts more than I thought they needed. There is now no deflection in them, they feel very taut.
Cranked it up this morning and it doesn't squeal.
Thanks for the help guys.