About a week ago the alt belt started making some noise...got bad enough this week that I changed it today. Squeal is still there....any ideas?

Serp or V set up?

V-set...all stock 1977 302 with no ac

I just changed to the 130 amp alt and introduced belt squeal. It only last about 1 second during startup. There are supposed to be some expensive belts that will stop the squeal. Something about v-belts with notches in the wide edge of the belt that increases pressure on the un-notched portion of the belt.

I havent tried to do anything to squealch the squeal yet.

I need to figure someting out...its my daily driver...nothing has changed, had the same setup for last 15k miles without any issue

Sorry, missed the "alt" portion of your post before.

Make sure the belt is properly tensioned. The typical V-belt should show about 1/2" of "deflection" when you press it with your thumb.

Also check out your pulleys and make sure the bolts are snug.

Belts are new as of today...pulley's cleaned...bolts snug.

Does not squeal at start-up or idle...squeal increases at RPMs increase; bad alt bearings?

I would guess going bad alternator or alternator bearings. I may still have the one off our 76 laying around, but won't know until I get off shift Tuesday AM. I am just across 34 bypass from you. Are you still across from the green one or have you moved? Have not your for a while.

That'd be great...yes, still live on 51st Ave...Bronco has been in the garage for the last 2-3 months...Let me know

As I said, I just did the 130amp 3G upgrade, that means I have a known good 2G alternator sitting around. It's yours if you want it.

Clay, I'll keep you posted...will be heading down to C/S in a couple weeks to see the in-laws....Thanks

On the way to church today, it stopped...don't know if the belt settled or something, but all is good now....Thanks again guys!

Royce - I looked and we still have the alternator that came off the 76. If it starts squeeling again or you want a spare let me know. Plus it would give us a reason to check out your bronco. You have a mustang too, don't you?

I'll take you up on the alternator...let me know of a good time for you to stop by or me to swing by your place. The mustang is my brothers, a 67 with 83k original miles. Thanks again!

I was having this same issue. I used the belt conditioner above and that worked for a while but the squeal started back up again. I thought the belt was tight but decided to see if I could get it tighter. I loosened both the upper and lower bolts on the alternator and took a big pry bar and wedged it under the alternator. I was able to get some serious leverage and tightened the belt up quite nicely. No more squeal for now.

My son was having a huge issue with his alt belt on his 66 stang, I mean the squeal was not onoly annoying, it was embarassing. He tried all the above measures, even tried scuffingthe belt and pully with 100 grit paper. No help. Finaly I stoped by the part store on my way home and bought another new belt. Problem solved and he has a spare for road trips.

Belt is new...tight to specs...pulley cleaned...belt conditioner applied...its a 50/50 chance its going to squeal on me...going to try a different alternator here shortly

depending on how much squeeling (slipping) the belt has experienced it may have gotten glazed even if "new"

I would try a new belt

Scott...Got the alternator installed tonight and the squeal is gone...my old pulley has a great polish to it, pulley would almost stop at idle....Thanks again guys!

Awesome. Glad it worked, and it was good to meet you. Jonah is hoping to take his maiden voyage on Monday. We will see!?!?!