# G alternator question

[rsev216]

I converted my 65, 289 to the 3G alternator using the original pulley. The belt continually squeals. It is especially bad when the electric fan or other high current items are on. I have swapped out the alternator but the noise is still there. Is this common? Do I need another pulley?

 

[cardude]

i am interested in this as well. I will be taking this task on in the near future.

 

[66HertzClone]

You need to look carefully at the alignment of the pulleys. I suspect the the alternator pulley is not in the same plane as the other two pulleys. This will cause a belt to squeal. Try to position a straight edge or even looking from the left or right side to check this. I think I remember reading something about having to shim these in order to get them to work.

 

[351w fastback]

i have the exact same problem. if i spray some belt dressing on it, it will stop but only for awhile and i want a permanant fix.

 

[hsr]

Guys,

In this diagram, there are comments on adding washers to shim either the pulley or top mount to cure the squeal issue.

I have a couple of other questions about this swap I haven't heard anyone else comment on:

1. Did you have to lengthen your lower mounting bracket as shown?

2. What did you do with your stock regulator and associated wiring?

 

[Tim65GT]

I first experienced belt squeal on my ‘Stang when I put a flex fan on it. I fixed it with a double pulley on the alternator and running a second belt.

I don’t know what model my engine came out of, but it is a '74 block and it already had a 3 groove pulley on the crank and a double groove on the WP.

I put a Vintage Air system on it this year and the compressor would only line up with the Supplied 3 groove crank pulley. Unfortunately it has a different configuration and now I’m back down to one belt on the fan and alternator again.

Although my belt squeal is only on start-up, I too, am looking for a solution. I would like a serpentine system some day, but I feel it's not going to be a weekend project.

 

[Swede958]

As far as the wiring, most will either just tie it up out of the way or trace it back to terminate the wires at their source.

I personally had to modify my bracket, but I had already switched to serpentine setup. As far as I know not much should have to be done as the mounting points are similar center to center, it's just the body that's much larger.

The squealing sounds a lot like a missaligned belt as stated- I would find a large straightedge or level or something and see exactly where the alt pulley sits in relation to the water pump... I'm gonna assume it's off.

 

[Tim65GT]

1. Did you have to lengthen your lower mounting bracket as shown?

I got my 3G from a '94 GT. It is the small case 3G.

Here is a side by side.

I think the bracket mods only apply to the large case type.

2. What did you do with your stock regulator and associated wiring?

I took the regulator off and used the Ignition wire (Green/red) and tied it to the white wire to feed excitation voltage over to the alternator (I).

I just taped back the other unused wires for now.

 

[hsr]

Thanks for the replies guys.

I don't have a 3G in front of me. Do you understand the part in the instruction sheet I posted about the bolt to activate the internal fan?

 

[Tim65GT]

I don't have a 3G in front of me. Do you understand the part in the instruction sheet I posted about the bolt to activate the internal fan?

The only part about a bolt and the fan that I see, it says put a bolt in one of the front holes to ENGAGE the fan.

The instuctions are for removing the pulley nut. You don't want the internals to rotate, so that's one way to hold it while you crank on the nut to remove it.

I wouldn't recommend that method. It will likely crack the case no matter which cooling hole you choose. It's best to use an impact gun and hold the pulley with a strap wrench. How do I know that?