I noticed today that my alternator seems to be making a sort of grinding noise. I tried to make sure it wasn't something else, checked a lot of other places that could cause the sound and the alternator seems to be the source. It kind of cycles between grinding noise and no noise. the car runs fine no problems, no electrical problems, I run a few accessories. A modern stereo dual electric fans, it doesn't seem to cause an excessive draw. Any ideas why it would make that noise thx.

could be the bearings probably the rear one in the alt. can you pop the belt off and run it for a few seconds to confirm if its the alternator?

Sorry it took so long to get back about this. Its definetly the alt. . so how does one go about fixing that bearing? I'm ok with fixing stuff not great or an expert by any means so is it something I could do? thanks

First, mark the two case halves so you get them back together correctly upon reassembly. The two case halves can be put back together in three different positions. This is called clocking.

Get a 5/16" socket. Remove the four bolts that hold the cases together. This will get you to the rear bearing when the rear case is pulled off. When you pull the case off, be careful as the brushes will pop out of their holder and you don't want to lose the brush springs. Drive the rear bearing out, drive a new one in. Put the brush springs back in their place, stick the rear brush in and hold it down. In the back of the rear case, you'll see a hole. Get a small drill bit, stick it in that hole and you'll see how the drill bit through the hole will hold the brushes in place while you put the two case halves back together.
You'll need a 15/16" socket and an impact gun to remove the pulley and fan to gain access to the front bearing. Under the fan, there is also a thin spacer that spaces the fan away from the front case. Once these are removed, you can pull the rotor out of the front case. You'll then see three screws, going through a retainer that holds the front bearing in the case. Remove the screws and retainer, drive the bearing out, drive a new one in and reverse the proceedure to put it back together.
After you replace the four bolts, pull the drill bit out to seat the brushes.
It's really very easy, but that's easy to say when you've done hundreds of them.

<BLOCKQUOTE>quote:</font><HR>Originally posted by popbirch:
I'm ok with fixing stuff not great or an expert by any means so is it something I could do? thanks<HR></BLOCKQUOTE>

Don't waste your time! If it's not the original unit, get a decent rebuilt one from NAPA or some other REAL auto parts store. Usually around 32 to 35 dollars. Not worth the aggravation. I paid around $35.00 for the one I have on the car now and it's been running for about 40,000 miles with no problems.


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MalibuJerry350
TC Member #1279
Original owner '70 Chevelle.
598,000 miles on car.
Hey, if it's got wheels, DRIVE IT!
My Chevelle: http://hometown.aol.com/erie614/myhomepage/index.html

But hey you have got to admit the blow by blow education of how to rebuild the alternator was too cool..... http://www.chevelles.com/forum/biggrin.gif
jaze70ss

Hey thanks guys, I think I'm going to have to go with the total replacement next time I come across 35 extra bucks(poor college student). Yeah the total rebuild way was cool, but maybe a hair over my head. I'm more of a if its broke just go get a new one and put it in. I can do R&R. Just out of curiousity is there some general time frame before it goes out completely or do I have a week or two? thanks again

i just got my new alternator, 27.99 at kragen, 55amp delco. and I get 10 bucks back when i return my old one. like they said, if it isnt orgional, i dont see spending anytime to check the alternator out.

imo, get one of those voltage gague, you will always know if your electrical system is working or not

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Alan

1969 Chevelle SS396 code 72 (http://www.cardomain.com/id/slpin)