Hi All,

I recently replaced my alternator and belt and now I'm getting an intermittent squeal I never had before. This is on an 87 LG4, so no serp setup here. Here's the situation:

When it's a little warmer out, I can cruise at 13 volts (most of the time). But if it's cool, I can get the gauge reading a couple clicks below that on a good day, but a stop or with the my headlights on, that thing will squeal for a good while. Sometimes I have to pop the headlights off at a red light and flick them back on once I'm cruising just to get the squealing to go away.

This makes me think that when the alt is under load, it's struggling too hard and that maybe it's time for a new battery, but I did replace the battery with a Delco only in February so I'm not thinking that's it. The alternator is pulled as tight as I can by hand when adjusting the belt and I don't see any signs of cracking or glazing on it. Is there somewhere else I should be looking? Thanks!

 

That happened to me on a Toyota a couple of years back (ok, like 15 years). It was a bad alternator and when under a charging load would create excessive drag on the belt drive causing it to squeal.

I would take the alternator off and have it tested.

 

Ah that's what I was afraid of. I just replaced this alternator with an o'reilly unit last month and it was working great for a while. These re-manufactured units are such a crapshoot - is there anywhere else I should look before turning this into game of yank and swap?

 

No one makes quality components for the CS130 anymore. Thus it is impossible to rebuild one in a quality fashion. If you want a reliable alternator look at DC Power Engineering or Mechman.

GD

 

Squeeling usually means the belt is not tight enough and is slipping. Any additional load on the alternator (like headlights) will make it squeel worse. This is very typical if you have removed it and put it back together. I know you said it is stretched as tight as it can go, but you put a new belt on. Maybe your new belt is longer than the old one...

Just noticed you said it was as tight as you can get it by hand. When I tighten mine I use a prybar to carefully apply more tension while I tighten down the set bolt to lock it in place. Every time I have set them only hand tight they squeel. I use the pry bar to get just a little tighter, not so much that it strains the belt.

 

Just a word of caution...
If it's too tight, you could wear out the water pump bearing quicker. Modern belts have tensioners and those can take all you give it, and not wear out bearings. The older style requires proper adjustment, with some give to the belt but not a lot. The noise might not be what you want, but at least the belt isn't too tight.

Also, the belt could be lubricated with candle wax while the motor is on (be careful doing that) or a fancy spray-on belt dressing product. That can quiet the noise without over tightening the belt.

 

My alternator starts squealing with new belts too.

Gauge was flicking too.

Cause was a broken plastic brush seat, then one brush was working in a diagonal position doing intermitent contact and high squeal.

Try other advices that you received here too. You are near to solution.

 

I eventually gave up chasing gremlins and just got a new alternator. Oreilly has a warranty on them for the lifetime of the item so I just swapped it out and now it's all gravy. Looks like it was just a bad unit all around.