Pretty sure it's the alternator, but to confirm...

[Christien]

Never heard of the woodruff key - just had to look it up, and no, I'm not at all positive that it's properly aligned and seated. I never saw it disassembling stuff (which is why I had no idea what you're talking about and had to search it) but it's entirely possible it just fell out and got lost. I'll pull it apart and look. Thanks!

[mca]

Originally Posted by Christien

Never heard of the woodruff key - just had to look it up, and no, I'm not at all positive that it's properly aligned and seated. I never saw it disassembling stuff (which is why I had no idea what you're talking about and had to search it) but it's entirely possible it just fell out and got lost. I'll pull it apart and look. Thanks!

Ya. That thing is easy to overlook. Sometimes it will fall off into a black hole never to be found when you remove the fan. Ask me how I know.

If you lost it, another can be found at your local hardware store.

[Wil Ferch]

Christien:

Woodruff key is a semi-circular piece of metal that fits into a longitudinal groove in a shaft, and the also on the piece being rotated.

Shameless plug...look at my alternator/voltage regulator repair article.... especially item 12 where this woodruff key is hinted-at.

Pelican Technical Article: 911 Alternator & Voltage Regulator Removal/Replacement

Also...for you guys saying you looked at the brushes and it takes $5 to replace.....I would advise AT LEAST having someone look at the copper slip rings that these brushes ride-on...they will likely be heavily grooved and should be replaced. Then the diode and bearing checks. A good alternator shop can do this and refresh/repair at reasonable cost.

[Christien]

I never thought to check the Pelican articles - I was just using the 101 book. That article is much more detailed - thanks!