Squealing altenator

[rasorbackq]

Question .... My alternator sometimes howls at startup if throttle too high after a warm up period it doesn't.
My squealing is the belt slipping and alternator not turning or is it spinning not just as fast as should. I see the rpms are about half speed when the squealing is there. As soon as the squeal goes away the rpm jumps right up.
Never fast enough to get the hood open to view.

 

[bspeedy]

Question .... My alternator sometimes howls at startup if throttle too high after a warm up period it doesn't.
My squealing is the belt slipping and alternator not turning or is it spinning not just as fast as should. I see the rpms are about half speed when the squealing is there. As soon as the squeal goes away the rpm jumps right up.
Never fast enough to get the hood open to view.

I'd be pretty confident that the belt is slipping. Some belts will slip even when they are tightened up. You may need to replace it.

 

[AWSubie]

If your situation is typical then your alternator belt requires re-tensioning. What concerns me is your statement about the rpm jumping, which is not typical.

 

[George2615]

It may just be a loose fan belt that has stretched. Belts stretch and need to be re-tightened. Belts that slip may become glazed (very shiny) and not have enough grip to spin the alternator pulley.
Try adjusting the belt tension or replacing the belt. While the belt is off spin the alternator pulley to make sure it spins freely.

 

[rasorbackq]

There is no more adjustment in the belt.
Think I will have to get one from Branson dealer as they are and odd size if I remember right.

 

[rasorbackq]

pulley spins freely.

 

[1stDeuce]

As a general rule, belts squeal because they are loose. The squealing stops because the belt gets hot from the slipping, and slips less, or the alternator catches up quickly and needs less power to turn. I assume the speed change you're talking about is the alternator finally coming up to speed...

A belt that is slilpping will wear quickly, even if it isn't squealing. You need to replace the belt and keep the new one adjusted better. If it's just a v-belt, any decent auto parts store should be able to match it up and provide a replacement. You might consider getting a ~1/2" shorter belt, if there is sufficient adjustment range to fit it.

 

[DLTTrekkers]

If it is an old mashine check that the pulley is stil in a v - shape and not a u - shape

 

[sd455dan]

Also V belt pulleys are designed to grip due to the belt being pulled against the pulleys V.
If someone has installed a narrower belt than the pulley is designed for or the belt is worn such that it begins to run all the way to the bottom of the grove, squealing can be the result.

 

[Slowpoke Slim]

If you have a Tractor Supply store near you, take the belt in with you. They have a pretty good selection of belts in inventory (at least the one here does). Or, if you have a Branson dealer nearby, they can order one for you I'm sure. A few of the dealers here can probably ship one to you direct if you need. Either Dave's or Mr. Bitz could I'm sure. I doubt it's a "special" sized belt.

 

[3Lfarms]

If your situation is typical then your alternator belt requires re-tensioning. What concerns me is your statement about the rpm jumping, which is not typical.

On some diesels, doesn’t the generator provide the tachometer signal?
I don’t know if an alternator can do that though.

 

[TractorGuy]

If there is no more adjustment the belt has either stretched beyond it usefulness or it had the wrong belt installed. Matching the belt up at TS is an option but you should find one a little shorter than what it has on it. According to this site the belt should be an A belt at 40.5 inches. I have often substituted L4 belts for A belts to reduce cost.

I would remove the belt with the engine cold and make sure the water pump and alternator spin freely with the belt off. Put a new belt on and check the adjustment after a few hours use and you should be good to go.

 

[rasorbackq]

If there is no more adjustment the belt has either stretched beyond it usefulness or it had the wrong belt installed. Matching the belt up at TS is an option but you should find one a little shorter than what it has on it. According to this site the belt should be an A belt at 40.5 inches. I have often substituted L4 belts for A belts to reduce cost.

I would remove the belt with the engine cold and make sure the water pump and alternator spin freely with the belt off. Put a new belt on and check the adjustment after a few hours use and you should be good to go.

Correct it is a 40.5 belt. Not sure if its stretched that long but would say a belt 2 " short could fit.
While I had the belt off I started the engine NO TACH indication at all stayed a zero rpm. Did the 1000 hr oil change

 

[TractorGuy]

2" is a huge jump in belt size. If it called for 40.5 I wouldn't go shorter than 40 on the first try.

 

[JRobyn]

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[Egon]

Belt dressing??

 

[CincyFlyer]

2" is a huge jump in belt size. If it called for 40.5 I wouldn't go shorter than 40 on the first try.

That has also been my experience; the new belt is, um, new, so it will be tighter anyway, and losing the 1/2" can be a whole bunch more than you'd think.

 

[rasorbackq]

You guys are so correct Tried to get a 40" belt on . Even took the alternator off but no go.
Bought a 40 3/8 today.

 

[rasorbackq]

Had to fight that 40 3/8 all the way. Had to remove the bottom bolt as well the top adjuster arm.
Now the adjuster arm is not used as its way too short to get the bolt back in. The alternator is about a mm off the motor .

 

[TractorGuy]

Guess the 40.5 is what it needed. Better make another trip to get one you can put on and adjust the tension on if you don't want to wipe out any bearings.

Tip: Belts are not actually the length printed on them. I use to think I could measure the circumference around the back of the belt and buy that size. Turns out most of the belts I tried to match up were shorter than the size printed on them.