belt squeal

[georgeramos]

My original alternator belt was squealing a bit and i tightened the tension and it quieted down but the alternator itself quit so i upgraded to a 95 amp and i cant get the belt to stop squealing. The one that i got with the new alt had it adjusted to the end of the slot but I bought a shorter belt that allows about 1/2 to 3/4 space left in the slot and i tightened the daylights out of it but the belt still squeals sometimes in a prolonged way for 5 to 10 seconds. This is particularly true on startup cold or hot. Might there be something else going on?

Thc

[chrisg]

I've had a few issues w/ a 95 amp alt. some was a bit of an alignment issue which I ultimately resolved. Some may be peripheral wiring related. The fact that it's on a car that is driven in bits (ie, maybe "daily" for 3-4 days at a stretch & then dormant for 3 weeks, etc.) makes it on a slow ride to diagnose as it tends to not be an issue when in regular use.

[Nanonevol]

How tight is tight? What's the play in the middle of the belt? (Just went through this)

[redcars]

It may be that your pulley on the car is worn out.

[georgeramos]

There is probably about 1/4 to 3/8 deflection. Its pretty tight. The pulleys look pretty parallel.

The squeal is much worse.upon startup ( cold or warm) and tends to go away.while driving and only come back periodically of driving for a while. It is getting very annoying.

[So Cal Mark]

the width of the belt has to match the pulley width or else you'll never get it to stop slipping

[georgeramos]

This happens to be a cogged belt. Could that make things worse?

I will pull it and measure the pulley width. Then i will search online i guess for a proper belt. Anyone have experience with AR 95 amp alternator and which belt fit the pulley?

[chrisg]

which side of the engine are you using it on? (mine is on my '71 and on the right side per original location for a BS1)

[grrrdot]

I've been having the exact same problem since installing the alternator, mine is on the passenger side.
The belt squeals on startup and occasionally when the cooling fan kicks in when my headlights are on.
I burned through the first belt very quickly, this second belt has been lasting awhile, neither were cog belts.
I noticed on my volt meter its <13V while its squealing so its somehow load related..

-G

[So Cal Mark]

high electrical load makes the alternator harder to turn. It's important that the belt is tensioned properly and is matched to the width of the pulley

[georgeramos]

It is on the right side here as well. I removed all the thin washers I had originally installed as "spacers" as I think they were placing the pulley too far forward. The alignment is better if not perfect. The squeal has been greatly reduced but still happens occasionally. It still always chirps on startup.

[klweimer]

What kind of shape is your battery in? If it's going south, that could make your alternator work harder at startup. You might just want to get a new belt. After a lot of slipping, it may be glazed to the point of no return.
Kirk

[johndemar]

You may have answered your own question with the spacer washers. I had to use a number of them to get the alignment just right.

[sptcoupe]

Had the same issue, and I think Mark has hit the nail on the head. The alternator pulley race is narrow on some, and the normal belt just doesn't seat deeply enough to not slip. I changed the belt and have never had a problem since.

[grrrdot]

It is on the right side here as well. I removed all the thin washers I had originally installed as "spacers" as I think they were placing the pulley too far forward. The alignment is better if not perfect. The squeal has been greatly reduced but still happens occasionally. It still always chirps on startup.

So how many washers did you end up with and where?
This is what mine looks like: