Alternator Pulley Issues - BBC - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**KyleSeal** · 10-24-2016, 10:52 PM

Having issues with alternator pulley. 1984 K30 454 w/ac.

First started when the alternator belt flew off and got destroyed on the fan, and resulted in a new alternator, but it still slips and will literally burn its way off. I fired it up the other day with a new belt, tight as I can get it, for 20 seconds tops. Belt was real hot. Other belts still ice cold.

Whats going on? Alignment is good. Not sure where to go.

TrailerTrash · 10-24-2016, 11:23 PM

lets see some pics of your pulleys and belts setup.

is there any squealing of the belt?

**KyleSeal** · 10-25-2016, 12:51 AM

Quote:

Originally Posted by TrailerTrash

lets see some pics of your pulleys and belts setup.

is there any squealing of the belt?

I'll get some up soon.

GRADYS Performance · 10-25-2016, 11:24 AM

Charge your battery before starting. A low battery puts a lot of load on the belt and pulley.

**KyleSeal** · 10-25-2016, 08:57 PM

Belt squeals loads before - I put a pulley from a SB350 alternator on the new alternator, and belt dressing, and drove some and it seemed okay... the battery was recharged by a local Carquest, and seems to be holding strong at 13.5/14.

kdh454 · 10-26-2016, 05:30 PM

This is probably not your problem, but I'll leave it here in case someone happens to make the same mistake I did.

I had a similar issue years ago after installing the engine in my Chevelle - alternator belt squeaked like crazy, got hot, and flew off. After several attempts at tightening and replacing the alternator, I pulled off all the pulleys to clean them up. Only then I realized the problem was mismatched water pump and crank pulleys. I don't remember exactly which was which, but I believe the crank had two identical pulleys and the water pump had one large and one small pulley. Basically, the alternator belt was being forced to slip around one of the pulleys, got fed up with it, and decided to end it's miserable life by being chopped to bits by the fan. I swapped out one of the pulleys, and all was right again.

TrailerTrash · 10-26-2016, 11:14 PM

Quote:

Originally Posted by kdh454

This is probably not your problem, but I'll leave it here in case someone happens to make the same mistake I did.

I had a similar issue years ago after installing the engine in my Chevelle - alternator belt squeaked like crazy, got hot, and flew off. After several attempts at tightening and replacing the alternator, I pulled off all the pulleys to clean them up. Only then I realized the problem was mismatched water pump and crank pulleys. I don't remember exactly which was which, but I believe the crank had two identical pulleys and the water pump had one large and one small pulley. Basically, the alternator belt was being forced to slip around one of the pulleys, got fed up with it, and decided to end it's miserable life by being chopped to bits by the fan. I swapped out one of the pulleys, and all was right again.

I had this exact same problem myself. that is why i asked for pictures of the pulleys

**KyleSeal** · 10-27-2016, 09:10 PM

Posted via Mobile Device

**KyleSeal** · 10-27-2016, 09:11 PM

This is the fan pulley. The first is the alternator.
Posted via Mobile Device

10-24-2016, 10:52 PM	#1
KyleSeal Senior Member Join Date: Mar 2014 Location: Toano, VA Posts: 884	Alternator Pulley Issues - BBC Having issues with alternator pulley. 1984 K30 454 w/ac. First started when the alternator belt flew off and got destroyed on the fan, and resulted in a new alternator, but it still slips and will literally burn its way off. I fired it up the other day with a new belt, tight as I can get it, for 20 seconds tops. Belt was real hot. Other belts still ice cold. Whats going on? Alignment is good. Not sure where to go. __________________ "Sometimes I do serve as a good bad example. Glad to be of service." My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809

10-24-2016, 11:23 PM	#2
TrailerTrash Registered User Join Date: Jun 2015 Location: PA Posts: 441	Re: Alternator Pulley Issues - BBC lets see some pics of your pulleys and belts setup. is there any squealing of the belt? __________________ - When the Reaper makes his deal, trust in your steel - '77 C10 350/350 2/4 drop and a mild street engine

10-25-2016, 11:24 AM	#4
GRADYS Performance Registered User Join Date: Dec 2013 Location: Columbus, Oh Posts: 367	Re: Alternator Pulley Issues - BBC Charge your battery before starting. A low battery puts a lot of load on the belt and pulley.

10-25-2016, 08:57 PM	#5
KyleSeal Senior Member Join Date: Mar 2014 Location: Toano, VA Posts: 884	Re: Alternator Pulley Issues - BBC Belt squeals loads before - I put a pulley from a SB350 alternator on the new alternator, and belt dressing, and drove some and it seemed okay... the battery was recharged by a local Carquest, and seems to be holding strong at 13.5/14. __________________ "Sometimes I do serve as a good bad example. Glad to be of service." My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809

10-26-2016, 05:30 PM	#6
kdh454 Registered User Join Date: Oct 2015 Location: Allen, TX Posts: 63	Re: Alternator Pulley Issues - BBC This is probably not your problem, but I'll leave it here in case someone happens to make the same mistake I did. I had a similar issue years ago after installing the engine in my Chevelle - alternator belt squeaked like crazy, got hot, and flew off. After several attempts at tightening and replacing the alternator, I pulled off all the pulleys to clean them up. Only then I realized the problem was mismatched water pump and crank pulleys. I don't remember exactly which was which, but I believe the crank had two identical pulleys and the water pump had one large and one small pulley. Basically, the alternator belt was being forced to slip around one of the pulleys, got fed up with it, and decided to end it's miserable life by being chopped to bits by the fan. I swapped out one of the pulleys, and all was right again.

10-27-2016, 09:10 PM	#8
KyleSeal Senior Member Join Date: Mar 2014 Location: Toano, VA Posts: 884	Posted via Mobile Device Attached Images

10-27-2016, 09:11 PM	#9
KyleSeal Senior Member Join Date: Mar 2014 Location: Toano, VA Posts: 884	This is the fan pulley. The first is the alternator. Posted via Mobile Device Attached Images



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