alternator belt is screaming ..... how tight shall I go???

[jglutz]

Very often not discussed clean...the belt and mating surfaces on the pullies.

As long as the contact surface of the belt is not glazed....a little laquer thinner or the like will provide a suffice cleaning.

Better yet buy a new belt if you have not already.

[Safety Guy]

Well, I bought a new rebuilt alternator and used the same (stretched, but nearly new) belt with it. It does make some squishy belt noise, but nothing loud.

I do wonder if I tightened it too much. Maybe I'll back it off slightly, or install another new belt.

Karl

[m715]

I had to change mine.... Hope this is the last of that problem for you. BTW, how much was the alt, and where did you buy it? Just curious.... I have one in the fleet with that type alt, and if you bought it from Hite, I wondered if it was Ford reman etc.....
Michael

[Safety Guy]

I got mine from A-Zone for $102. Core was $52.

It seems to be making more noise now, so I'll install the new belt soon.

Thanks for the help, guys!

Karl

[vectormechanic]

When you deflect the belt 3/8 in., you should be pushing about 20 lb. If you get some squeals after that, try 22 lb. I'm not basing this on official specs, just general knowledge. As for method, an alternative to using a straight edge: Make a hook on each end of a straight wire (like from a clothes hanger) and hook the belt with it halfway between the crankshaft pulley center and the alternator pulley center (if you only have 3 pulleys - I don't know what it's like if you have a/c or p.s.). Pull with the wire pretty much perpendicular to the run of the belt you're pulling on. Pull with a spring scale that goes up to about 25 lb. mark the wire with chalk and use some part in the engine compartment as a reference point. Pull with 20 lb or so and see if you have 3/8" deflection. Err on the side of looseness - then if you don't have a noise, you know you're good. With a new belt, the shop manual says you don't need to wait a month; just run it for 10 minutes and readjust. I suspect they are right, but I haven't checked it out yet.

[miami man]

recently mine did that then the belt broke. put another one on and the sound went away.

[miami man]

ok now the sound is back