951 Alternator R & R
 

Guys I'm a newcomer so please be gentle. First off this forum is awsome.
The technical expertise is mind boggling.
I have to admit I've been one of those 911 snobs responsible for keeping the 944 series more affordable but after purchasing a 951 in December I have not been able to contain myself. So if the price hike has been going up quicker since the new year, guilty as charged. Everything is so much better designed and the handling.....!
Porsche must be embarrassed that they ever let it stop evolving and die with the 968.

Anyway I'll jump right in now.
It's time to replace the alternator.
VMeter says it's only putting out 11 volts. (BTW does this effect the performance of the car? DME, Turbo spool up, etc)
Why does the 944 series eat Alt brushes faster than others?
I've seen here that this job is pretty labor intensive. How bad? How many hours do I allow for? Any special tools, other than replacement knuckles?
When the alternator gets rebuilt what else gets replaced besides the brushes?
How much more could it be to get the complete rebuild treatment rather than just the brushes and regulator if the biggest pain is the remove and re-install.

Removal of the alternator can be a PITA, but it's not all that difficult. The basic process is to remove any interference items over the alternator, loosen the ribbed belt, disconnect the battery, disconnect the alternator, and then remove the mounting bolts.

What gets replaced during a rebuild depends on the rebuilder. Typically the rebuilder will replace the bearings, voltage regulator, media blast the case, and re-wind the stator and rotor if necessary.

Replacing the voltage regulator and brush rigging is fairly easy. Once you gain access to the rear of the alternator, you remove the screws for the regulator, pull the old one out, put the new one in, put the screws in, and then put back anything you had to take out to get to the alternator. Sorry for being a little unclear, but I have two NAs, so I'm not really familiar with what is in the way on a turbo.

As for having the alternator rebuilt, you can do that, but it is much easier to exchange your current alternator for one that has already been rebuilt. Most places like NAPA, Pep Boys, Auto Zone and Advance Auto do this every day. You can even get rebuilt units from several vendors on the web, but I would stay away from Vertex Auto. I got a rebuilt alternator from them for my '84, and it was a POS. The workmanship was very poor and the alternator lasted less than a month.

Napa stocks a 951 alternator for $120.00. The only hang up is that this alternator does not have the correct studs to install the plastic air duct. So you need to swap the studs. Otherwise its a cheap replacement. I too was reading 11V or less, now I am closer to 14V even with accessories on.