Alternator squeak

[numatik]

Hey guys, im sorry if this is in the wrong category, if it is could I have a mod move it to the correct place, thanks!

I have a 2004 Silverado show truck, it has a 4.3l v6, with A/C. It has a 300 amp boss alternator. Whenever the truck is cold, I start the truck and it starts squeaking. Sometimes when I pull out of the driveway it will squeak alllll the way down my street. I called an alt shop and gave him the symtoms, and he gave me something to try. He said start the truck when its cold, let it squeak for like 5 seconds, then shut it off, and run under the hood and very quickly just touch the alts pulley. It was burning hot, and he said thats a sign the belt is physically squeaking on the pulley, because if it was free spinning it wouldnt heat up that fast since the friction of the belt slipping would make the pulley that hot in no time.

I called boss alts, they were no help at all. he didnt have any way to fix it, he said find a local alt shop (which i did) and ask them to fix it. he said if they couldnt fix it to just send it back. he said he had never gotten a phone call with this problem and hes sold hellla alts for a long time.

Before these phone calls, I replaced the belt, tensioner, and idler pulley, and was advised to NOT use belt dressing.

What should I do next? i was recommended to try a different belt called a gatorback by good year, what do you guys think? Im going to post this in my project thread too so more ppl see this thread

Please somebody help!!

[Go-N-Def]

i think it means bearing are going out. if the alt is old or have cheap bearings.

[95legwagon]

i think it means bearing are going out. if the alt is old or have cheap bearings.

this

also does it have a belt tensioner thats adjustable or a spring loaded tensioner? i was asking because if you tighten your belt too much you can wear out the bearings in the alt quick causing that fimiliar sqeak.

good luck

[Socky]

Can you move the alternators pulley, or atleast turn it over see if it spins by hand?

[kickass audio]

Typically a hot pulley usually means that you have belt slip. It doesnt always indicate a bad bearing. You could buy a listening probe and put it on each of the pulley's to listen for any grinding or squeaking noises as that will help you pinpoint what pulley may be the culprit.

Here is what i would try:

Remove the belt from the engine. With the belt off all the pulley's take your hand and put it in the 12 and 6 o'clock positions and attempt to rock the pulley up and down. Then take your hands and put them in the 3 and 9 o'clock positions and attempt to rock the pulley left and right. If the pulley rocks then your bearing for that pulley is on its way out.

I also had the occasional belt squeal on my envoy when it is somewhat warm out toward the end of this fall. I just sprayed some lithium grease to the back side of the pulley's as they were not wobbling at all and it fixed it for the most part. Sometimes i get the occasional squeak but its not as loud or as long as i had before i sprayed them.

I would also highly recommend you get brake parts cleaner and a clean rag/towel and clean all your pulley's off. Spray the brake part cleaner on the rag/towel then wipe the part of the pulley's that the belt rides onto. Make sure you do this until they have no oils left on them or when you wipe the pulley you cannot see any dirt collecting on the rag. I did this to all my pulley's and my belt without any problems. But to be safe i cleaned the pulley's off and installed a brand new belt from advance auto on my truck and its been fine, i have had no belt slip.

Hope this helps!!

[numatik]

i think it means bearing are going out. if the alt is old or have cheap bearings.

this

also does it have a belt tensioner thats adjustable or a spring loaded tensioner? i was asking because if you tighten your belt too much you can wear out the bearings in the alt quick causing that fimiliar sqeak.

good luck

I has a spring tensioner, and I replaced it 3 weeks ago. The alt is old, its been in since like 06.

Can you move the alternators pulley, or atleast turn it over see if it spins by hand?

Typically a hot pulley usually means that you have belt slip. It doesnt always indicate a bad bearing. You could buy a listening probe and put it on each of the pulley's to listen for any grinding or squeaking noises as that will help you pinpoint what pulley may be the culprit.

Here is what i would try:

Remove the belt from the engine. With the belt off all the pulley's take your hand and put it in the 12 and 6 o'clock positions and attempt to rock the pulley up and down. Then take your hands and put them in the 3 and 9 o'clock positions and attempt to rock the pulley left and right. If the pulley rocks then your bearing for that pulley is on its way out.

I also had the occasional belt squeal on my envoy when it is somewhat warm out toward the end of this fall. I just sprayed some lithium grease to the back side of the pulley's as they were not wobbling at all and it fixed it for the most part. Sometimes i get the occasional squeak but its not as loud or as long as i had before i sprayed them.

I would also highly recommend you get brake parts cleaner and a clean rag/towel and clean all your pulley's off. Spray the brake part cleaner on the rag/towel then wipe the part of the pulley's that the belt rides onto. Make sure you do this until they have no oils left on them or when you wipe the pulley you cannot see any dirt collecting on the rag. I did this to all my pulley's and my belt without any problems. But to be safe i cleaned the pulley's off and installed a brand new belt from advance auto on my truck and its been fine, i have had no belt slip.

Hope this helps!!

THAT I think is the answer, I did not try that till just now! alt spins freely, BUT if you grab it just as kiackassaudio sad it DOES have a little bit of play. I think its the bearings!!!! I'll take it to the local alt shop the next day there open (hopefully 2marro but they may be out for the holidays). Are alt bearings pretty universal, or am i going to need to get them from Boss alts?

In the meantime Im gonna clean the pulleys the best I can with brakeclean. Problem is with a towell I cant get get into the grooves, I think im gonna need to take a wirebrush to them. After cleaning and drying the best I can do I let the truck sit for a few hours with the hood up to try and evaporate everything completely dry?

[numatik]

I called the alt shop and explained what i read on here, he still says its not the bearings because the sound wouldnt go away then come back when its cold. Next week he said to bring the alt in and just put it on the test bench and see if we can get it to squeak. If we cant get it to its possible to eliminate that, but I dont have a listening probe, and im not sure where else to look.

I read earlier on a diff thread about people replacing parts of the ac that could be the squeak as well... is there anything else I should try in the meantime before I take the alt in?

[Mad_Mike]

If the alternator's pulley was really hot when you ran the truck for only 5 seconds then yeah it's definitely belt slip.. Try to make the belt slip by just pulling on it, if you can make it move then your tensioner is bad. Otherwise it's probably bad bearings in the alt, try to replicate what the belt is doing.. On one of those "cold mornings" pull the belt off the alt and see if it will spin, then put pressure like the belt would and see if it spins.

[numatik]

If the alternator's pulley was really hot when you ran the truck for only 5 seconds then yeah it's definitely belt slip.. Try to make the belt slip by just pulling on it, if you can make it move then your tensioner is bad. Otherwise it's probably bad bearings in the alt, try to replicate what the belt is doing.. On one of those "cold mornings" pull the belt off the alt and see if it will spin, then put pressure like the belt would and see if it spins.

The tensioner, idler pulley, and belt have all been replaced recently. I will try that 2marro when the truck is cold, so just pull the belt and spin it with my hand? If the belt is slipping what other component do you think is likely to have something to do with the slippage? I dont know why it wont grab the alt without slipping, but after a minuted or a few, the alt does keep the batteries charged no problem at all

[numatik]

I got the alt back from the shop today, he replaced the brushes, the tolerance ring around the hearing (which was cracked) and new bearings. The speak is GONE! Well that one is..... That big squeak that I wanted to fix is long gone, and now the ac is just starting to make a really low squeak, not that loud at all tho. 2marro im picking up a new ac clutch bearing and im gonna swap that out before this thing is squeaking like crazy how it was. But I am very happy that problem was finally fixed, it was driving me CRAZY. So fucking annoying!!