Are you kidding me? Squealling coming from generator

[cllctrtom]

A few months ago, I started to get a high pitch squeal from my generator. The squeal would go away when the accessory switch was turned off but of course the vehicle wasn't charging. I replaced the generator the other day and low and behold after about 10 min. of running it started to do the same thing! What is going on and why does it do this?

Can someone shed some light?

Thanks in advance!

 

[clinto]

How tight is the belt?

 

[cllctrtom]

How tight is the belt?

1 belt is 1/2 and the other is 3/4 inch play. But why does the noise stop when the switch is off?

 

[gimpyrobb]

It doesn't produce power till its "turned on" by the switch.

 

[EWhytsell]

When the switch is on there is a load placed on the generator. Switch off and its free wheeling so no belt squeaks and no other noises. Some noticable noise should come from it when its under load, but it shouldn't be noticed standing outside the truck with all the other vibrations/noises.

 

[clinto]

When the switch is on there is a load placed on the generator. Switch off and its free wheeling so no belt squeaks and no other noises. Some noticable noise should come from it when its under load, but it shouldn't be noticed standing outside the truck with all the other vibrations/noises.

Bingo!

I've always done it by feel (i.e. how tight to make the belt) but there is actually a tool to measure belt tension. Of course, you'd have to know what the spec is for the tension for this to help.........

http://buy.snapon.com/catalog/item....675585&supersede=&store=snapon-store&tool=all

 

[cllctrtom]

When the switch is on there is a load placed on the generator. Switch off and its free wheeling so no belt squeaks and no other noises. Some noticable noise should come from it when its under load, but it shouldn't be noticed standing outside the truck with all the other vibrations/noises.

The noise is unbearable. You can't be anywhere near the truck and the sad thing is we use it in parades. Why is it squealing?

 

[cllctrtom]

So if it is the belts, how tight should they be?

 

[clinto]

So if it is the belts, how tight should they be?

This is gonna' sound smart alecky, but tight enough for it not to squeal and loose enough not to burn up alternator bearings.

Also, those belts are designed to be a matched pair, meaning both belts cut from the same piece. So they are both identical to one another. Ask your parts house for a matched set, they'll know what you mean. I'd replace em if one is longer than the other.

 

[gimpyrobb]

This is gonna' sound smart alecky, but the only load with the switch on is the batterys. Then if he turns on lights and stuff, there is more load.

What condition is your batterys in? Do you have the right sized belts? I had some that would not tighten up when my adjuster was ALL the way out. Turns out the belts were too long.

 

[cllctrtom]

This is gonna' sound smart alecky, but tight enough for it not to squeal and loose enough not to burn up alternator bearings.

Also, those belts are designed to be a matched pair, meaning both belts cut from the same piece. So they are both identical to one another. Ask your parts house for a matched set, they'll know what you mean. I'd replace em if one is longer than the other.

To be honest, I would have bet a hundred bucks it wasn't the belts but what you, (and others) are saying makes sense. I will get a matching set of belts and get them tightened properly and see where that takes me.

In short, I wasted my time changing generators?

 

[clinto]

This is gonna' sound smart alecky, but the only load with the switch on is the batterys. Then if he turns on lights and stuff, there is more load.

What condition is your batterys in? Do you have the right sized belts? I had some that would not tighten up when my adjuster was ALL the way out. Turns out the belts were too long.

This is gonna' sound smart alecky, but if the belts have been slipping, the batteries may not be fully charged, which means the alternator is under a heavier load trying to recharge them.

To be honest, I would have bet a hundred bucks it wasn't the belts but what you, (and others) are saying makes sense. I will get a matching set of belts and get them tightened properly and see where that takes me.

In short, I wasted my time changing generators?

Don't know.

Did you, before swapping:

A. Put a multimeter on it and check the output
B. Check the bearings to see if the pulley turned smoothly

?

 

[gimpyrobb]

In short, I wasted my time changing generators?

Nope, you learned a lot.

 

[gimpyrobb]

This is gonna' sound smart alecky, but if the belts have been slipping, the batteries may not be fully charged, which means the alternator is under a heavier load trying to recharge them.

Yes, but the switch doesn't create the load, the switch just turns on the charging circuit.

 

[cllctrtom]

This is gonna' sound smart alecky, but the only load with the switch on is the batterys. Then if he turns on lights and stuff, there is more load.

What condition is your batterys in? Do you have the right sized belts? I had some that would not tighten up when my adjuster was ALL the way out. Turns out the belts were too long.

Batteries are less than a year old. Not sure if the belts are the right size. I can only assume.

You guys answers are great and I appreciate everyone's help!

I spent 20 years in the military and can operate anything from a M48 to M1 series tank but can't figure this **** squeal thing out! Go figure.

 

[cllctrtom]

This is gonna' sound smart alecky, but if the belts have been slipping, the batteries may not be fully charged, which means the alternator is under a heavier load trying to recharge them.



Don't know.

Did you, before swapping:

A. Put a multimeter on it and check the output
B. Check the bearings to see if the pulley turned smoothly

?

A. Didn't check voltage
B. Generator spun fine. In fact a little better than the new one.

 

[clinto]

Yes, but the switch doesn't create the load, the switch just turns on the charging circuit.

Ok, all joking aside now..........

Isn't the activation of the charging circuit what creates the load? I.e master power switch is off, belt is simply turning the reciprocating mass of the alternator. Switch on, alternator "sees" battery voltage and attempts to charge, alternator sees load, belts squeal, tom posts, etc.?

 

[gimpyrobb]

I would look very close at the belts. It wouldn't surprise me if they have been glazed over too. The correct numbers escape me right now, I'm at work(farting around on company time!).

 

[DieselBob]

Also be sure to check the alignment of the belts on pulleys.

 

[cllctrtom]

Also be sure to check the alignment of the belts on pulleys.

View attachment 433568

Alignment is good. That is one thing I checked after putting new gen on.

Thanks!