Alternator Replacement - Tips

[911Atlanta]

I just replaced the alternator in m '87 911, and have a few tips for the non-experts out there (like me). This assumes you've read the tech articles and other threads on how to actually do the job.

-- take a few photos if possible, you'll be glad you did. Like many projects, you won't remember as much as you think you will. Even a close up with your cell phone is better than nothing.

-- the outer nut on mine was very difficult to loosen; my regular ratchet was starting to slip off from all the pressure and started to round off the edges. If yours is way tight, use a breaker bar to get it done once and avoid the catastrophe of rounding off those edges.

-- don't be afraid to bend that flexible metal strap out of the way; it will bend back in shape just fine.

-- before you remove the air deflector thing from the back of the fan shroud/alternator, take a sharpie and make a mark on both the air deflector and the back of the fan where they connect. this will help line them back up when you reinstall. Believe me, it won't be obvious where they reconnect later. Keep in mind that the vanes should point left side of engine -- the wind is naturally blown to right side of engine and this compensates.

-- when reconnecting the air deflector to back of alternator/fan, don't tighten the nut down too hard or it will break the plastic.

-- when you reinstall the belt, it will seem very loose until you tighten down the outer nut. You've probably got the correct size belt, don't worry, it will cinch up when you tighten the whole package down.

-- while you're working, pull out the battery and charge it up outside the car. I believe charging/over charging the battery while it's in the car can fry the alternator.

Good Luck !

[Formerly Steve Wilkinson]

One other mini-tip: A year or two ago, I installed a brand-new alternator, and somehow, while replacing the air deflector with all the little nuts and both flat and lock washers that hold it in place, I dropped one of the washers somewhere. Didn't think much about it, figuring that one tiny washer wasn't going to do any damage, probably fell through some cylinder cooling fins.

In fact the washer bounced inside the air deflector and popped into the alternator, neatly bridging the gap between the windings and the alternator case.

Got into the cockpit, turned the key on, and in 10 seconds there were huge clouds of smoke. Fortunately, I have a master switch and immediately cut off the current, but it still required a brief blast from my fire extinguisher through the fan to put out burning insulation.

Trashed the never-run alternator, of course,and required replacement of all the alternator wiring.

So the tip is, hang on to the little washers...