Alternator Replacement

Ok, so the used alternator I got is going out. I can hear the bearings are about to out on it. So I am going to replace it tomorrow. I just got a Viper alarm installed and was wondering if I should replace the alternator with a performance one or if an OEM style alternator would work fine. Its a 94 Z.

If you have a after market stereo I would say go with a hi output alt.

Nope, no beefed up stereo. Not really into that stuff, just the alarm and that's all its going to have. So, I guess I'll stick with the OE style one.

And another question, how can I tell which voltage alternator my car needs? The 94 LT1's came with either a 125 volt or 140 volt and I don't know which I need. I don't even know if the one I have now is the correct voltage, since its not the one that came with the car. I'm going to Autozone, is there a way that they can test which voltage it is since it seems to be working with the car fine?

125 volt? You running a tv or something? I'm going to assume you mean 125 amps. Go with the 140 amp. You won't hurt anything by having a higher output alternator, just means you can draw more if you decide to run an amp or something later down the road.

Well, finally got a repair that was easy this time. Went to Autozone and turns out it was the 140, so got that and slapped that on. Works fine and stuff, but the noise came back once with the new one.

The reason I replaced the old one was because I thought it was making an odd high-pitched noise sometimes at idle, that would go away and come back. Sounded like it was coming from the alternator, and that the bearings were going out. Its also what my dad thought. But that may not be it since it has done it once with the new one. Out of ideas, but it sounds like its coming from the passenger-side half of the motor. Any ideas?

Check the rest of the pullies. Sounds like a carrier bearing in one of them is failing. My ac compressor in my grand am made a hellufa racket until I swapped the compressor.

Yeah, that's what I am going to do. My guess its the pully right underneath the alternator. I may have to replace that. Thanks Skibum, I'm glad you had the same idea as me.