I got mine back from the rebuilder. New regulator, bearings and he said they fixed a worn shaft too. It actually looks like a different unit.

And its installed and running well. At startup, voltage was approx 14.1 or 14.2 by eyeball on the dash gauge. After running a while (it was at night, lights on), it settled down to 13.8 or 13.9 (again by eyeball on the gauge). A definite improvement on the old unit.

Couple of points:

1) REALLY LISTEN to the suggestion to disconnect the battery before you do this DIY. I had not. It's amazing the sparking that went on when the big cable to the alternator is unplugged and you let it drop and bounce around the engine block...(!)

2) The new regulator had 2 "channels" for putting on the big cable to alternator whereas I think (from memory) the OEM one had just one. Maybe that's so that it can accommodate differences in different cars. Anyhow I had thought that I had put it in the better channel the first time but I was wrong. I could not align the bolts onto the bolt holes no matter what I tried. It looked close enough but it just wouldn't go on. Got really tired. I then swapped the cable to the other channel and the installation and alignment was a breeze. The incorrect orientation of the cable must have been holding up the install by the cable being in the way of the alternator going back in.

3) One thing, if you guys are replacing the just regulator and are re-using the same body, you really should press back the bushing on the right-hand backside mounting arm. Otherwise you will have to hammer it in like Sameer did. I noted this in another DIY posted on the Internet. On my unit, the rebuilder pressed the bushing back as part of the service (or they gave me a re-man unit) and the unit slipped right in with room to spare; no hammering needed.

4) remember your radio codes before disconnecting the battery(!)

 

Nice pictures

 

I just finished replacing mine today. I pulled my old one off (2003 MY04 996t) and it was this part number:



Porsche now recommend a 150 amp part number, 997 603 012 07, $1100 from Sonnen. I ended up going to my local Bosch dealer and reordering the same part number as what came off:



$400 brand new, you couldn't pay somebody to rebuild your old one for that. I started it up and from cold it was charging at 14 volts and when warms drops back to about 13.5V

 

Old thread I know, but figured Id comment here.

Just did this today- symptoms were got at ABS and PSM warning after 5 minutes of driving. 16 minutes later, parked. Came out after 5 minutes, no crank. Pushed it. Started, drove. Get a 'generator' wanring, voltage drops to 9V, then battery warning...car would not rev over 3k....In about 45 seconds later voltage popped up to 12V but red warning remained. Drove home, parked it.

Bought a Bosch remanned on amazon for 392, no core.

Followed this DIY-

One big note. See this picture:




On the mounting point shown at the top in the picture you can see where the long bolt attaches- note that the bolt screws INTO the steel 'busing' that is mounted within the rear-most mounting point. This is key: that bushing is free to move in and out- in fact the rear of the alternator is held by that bushing, but is not clamped at that point. If you look at the picture you can see that the bushing has been 'pulled' up towards the front of the alternator by the long bolt, 3-4mm. Compare it to your new alt, you will see the difference. (New the bushing is even with the aluminum casting.) The problem many have is the alternator is clamped in place even after the bolt is removed- and that bushing is corroded and is holding the alt in place. The trick (and this is in the factory instructions) is to unscrew the long bolt THREE complete turns, then whack the bolt back in (use something on the head), pushing the bushing back in. This will allow the alt to be hand manipulated. (You might be able to spray something back down there if yours is corroded.)

Took me about 2:20, this DIY was very helpful.

A

 

Thanks Sameer great help brother Reps for you +1

 

Just replaced mine (2002 turbo, 52k miles). Good write up, helped a lot.
Couple of learning points / additions:

1) photo 6, sensor on y pipe, the 6mm bolt froze on the pipe and broke on removal (needed to install a helicoil). I'd just unplug the sensor if possible next time.

2) The clutch on the alternator pulley failed, which caused voltage to drop off, not the regulator. I took the alternator to Tucson Alternator Exchange (TAE), they diagnosed the problem. If you hear a "knocking" noise or looseness when rocking the pulley back-and-forth, it's a bad clutch.

3) TAE charged only $150 exchange.

 

I have both alternator bolts out, but alternator not coming out easily. Rocks a bit on left side (short bolt side). Have only used hands thus far, no pry bars, hammers, etc. Can anyone confirm @ard post from 2013:



Great thread overall.

 

I used a pry-bar applying slight pressure on several areas of the housing until it came free.

 

This bushing (arrow) is a floating bushing, you can apply a couple of drops of release oil on it may be it is seized....

 

I've been doing DIY for almost 30 years, and I completely agree that making some space is faster. However, in this circumstance, it is simply not possible. The items that are impeding you aren't as simple as a few bolt clamps here and there, clips, or ties from https://www.scrooz.com.au/hardware/joist-hangers/. It removed everything. No, the issue is a flat sheet metal bulkhead. Or a harness bundle that is easily 25mm/1" or larger does not bend and would require the engine's dewiring. Simply put, not everything can be eliminated to gain access. Sometimes you're just out of luck. I just pulled that thing back together.

 

Just replaced mine last night expecting it to take ages. 50mins in and out and back together. One of the easiest jobs ive done on this and many other cars.