Alternator help

[nate12346]

Ok So coming home my truck starts makin a very loud almost whistle noise at certain RPM's. I start lookin around under the hood and its not my intake whistling. I touch the Alternator and it feels like it is vibrating at a very high frequency and makes it sound like a whistle. It still charges no problem.

My question is:

Can I lube the alternator? Like WD40 sprayed all in it?(possible fire potential?) Or should I just get a new one?

[dusto2]

new one bearings are probably shot

[97ranger xlt]

just had that here. junkyard alternator ($25.00) solved it.

[Wicked_Sludge]

the bearings on these alternators are sealed and supposedly non-serviceable.

that said, i hosed the crap out of mine with penetrating oil when it started squealing and havnt had to mess with it since. that was 4 years ago...:yahoo:

[Ranger5.0]

is it a wistle or more of a whine? some times when the diodes start to fail it will make a wheering kinda noise

[triumphrider-1]

Not to thread-jack, but has anyone just relaced the bearing(s) in the alternator before?

[martin]

yes, lots of times. on various different vehicles.

[holyford86]

I just recently got mine rebuilt, New brushes, regulator, bearings, and rotor. Cost me about 50 bucks. the brushes in mine were shot and the bearings were also, was growling and wouldn't charge sometimes.

[Will]

We still have an old fashioned auto electrical shop in Columbus Indiana. It's a better bet than an assembly line overhaul.

[Shran]

I always get my alternators and starters rebuilt by a place here in town. Saves the hassle of getting the wrong replacement and is loads cheaper.

[snake]

Don't use WD40 as a lubricant because it isn't- its a penetrant. You can verify its the alternator with a stethescope, and if that's it shoot it with some lube and see if it stops. Shouldn't catch fire...