Squeaky alternator belt

[onebadd73]

I recently did a 3g alternator install and since then my alternator squeaks for a few seconds at start up. I have the correct belt size and ithe belt is fairly tight on there. I noticed that pulleys are now glazed. I took them off and sanded them down a bit to scuff them, but that didn't work. I also tried some belt dressing but I think that helped glaze the pulleys. The funny thing is that at night when I turn on the headlights the belt will squeak, as soon as I turn them off it stops squeaking. This is a real pain in the a.. Ant suggestions would be appreciated, Frank

 

[73stallion]

3G alternators are famous for this. the guts are heavier, so they like to squeak with V belts.

i use a heim joint adjuster on mine. i run the belt a hair tighter and i have no problems at all with it squealing.

 

[onebadd73]

Where can I find a heim joint adjuster like that ???

 

[72Sport]

The 3 G probably puts out at idle close to twice what your stock alternator put out at full throttle. Even with serpentine belt squeal can be a problem. If you get the belt too tight you "might" put too much load on your alternator bearings. You might consider installing a larger pulley on the alternator to slow it down a little. The larger pulley will also provide more belt wrap on the pulley. Meaning it spreads the load over a larger belt area so it doesn't slip. A longer belt will also help add more belt rap on the pulley. A 1/2-3/4 inch increase in diameter will help a lot. It will probably reduce your idle output to about 60 amps. I haven't checked it.

The 3G probably puts out about 80-90 amps at idle. Your stock alternator was probably rated at 45 amps.

I put a larger pulley on mine. With serpentine you don't have many choices. The 3g feeds my ac and electric fans with no squeal.

 

[73stallion]

zoops makes them, they ain't cheap! expect to spend about $30 on one. check ebay and hotrod shops.

 

[Pa PITT]

How are you at rigging ...if you can come up with a back idler pulley and can get a little more around the circle of the pulley on the alt this might keep it from
screaming i did this to a dodge tr. once..

 

[ponch0v]

The 3 G probably puts out at idle close to twice what your stock alternator put out at full throttle. Even with serpentine belt squeal can be a problem. If you get the belt too tight you "might" put too much load on your alternator bearings. You might consider installing a larger pulley on the alternator to slow it down a little. The larger pulley will also provide more belt wrap on the pulley. Meaning it spreads the load over a larger belt area so it doesn't slip. A longer belt will also help add more belt rap on the pulley. A 1/2-3/4 inch increase in diameter will help a lot. It will probably reduce your idle output to about 60 amps. I haven't checked it.

The 3G probably puts out about 80-90 amps at idle. Your stock alternator was probably rated at 45 amps.

I put a larger pulley on mine. With serpentine you don't have many choices. The 3g feeds my ac and electric fans with no squeal.

When you put a load on the alternator (at startup when the alternator turns ON, putting the head lights on, etc) it takes more to spin the 3G. With the v- belt there is just not enough surface area in contact with the pulley. You may try a brand new belt that is a little softer compound, Goodyear belt maybe??


I had the same squeal issues and finally changed over to the serp belt, no more promblems.

Never heard of a serp belt sqealing unless its really old and hard.

Also, over tightening the belts will but more side load on the water pump and alt bearings and seals.

 

[onebadd73]

I have an large aluminum underdrive pulley from JBA that I bought at a mustang shop, I'll swap it out and see if that fixes the squeals until I go to a serpentine system someday..

 

[DirtDonk]

When my belts were squealing under the same circumstances I did the sanding routine but also used a good dose of Chemtool carb cleaner to deglaze the pully grooves.
Worked pretty good, but I did it one better when I changed to dual-groove pullies. That let me take some of the extra tension out of the belts so I felt better about bearing life.

Serpentine is sitting on the deck, waiting it's turn though.

Paul

 

[RRRAAAYYY2]

Serpentine is really the best answer. Pain in the butt to install, but is well worth it. The tension arm pulley will keep the belt at its proper tension during your engines operating cycle. Did you know that the tensioner can adjust your belt tension over 80 times a second?
A good working tensioner adjusts the belt tension every time a plug fires. That is because the belt stretches a small fraction when the force is applied to the crank pulley, and then shrinks back when there is no force.
So when you look at the tensioner while it is operating, it should be moving back and forth a little bit. GM's move way more than Fords, but there should always be some movement.
Studies indicate that over 40% of all vehicles on the road have a defective belt tensioner.

 

[Skuzzlebutt]

As usual, RRRAAAYYYs right. Paul too.
It's not just 3Gs. Any high output alternator is going to strain an old fashioned V belt.

 

[BwoncoHowie]

This has worked for me on occasion.

The 3 G probably puts out at idle close to twice what your stock alternator put out at full throttle. Even with serpentine belt squeal can be a problem. If you get the belt too tight you "might" put too much load on your alternator bearings. You might consider installing a larger pulley on the alternator to slow it down a little. The larger pulley will also provide more belt wrap on the pulley. Meaning it spreads the load over a larger belt area so it doesn't slip. A longer belt will also help add more belt rap on the pulley. A 1/2-3/4 inch increase in diameter will help a lot. It will probably reduce your idle output to about 60 amps. I haven't checked it.

The 3G probably puts out about 80-90 amps at idle. Your stock alternator was probably rated at 45 amps.

I put a larger pulley on mine. With serpentine you don't have many choices. The 3g feeds my ac and electric fans with no squeal.