Need Help with alternator install'l.

GC 53 · GC 53's Garage

first timer here with working on the P-cars.
I have a '78 SC that needs the alternator replaced.
I also have a copy of "101 Projects". I'm at the part where I am trying to pull the housing forward to disconnect the electrical wires off the back of the unit. But can't quite get it out more than maybe 3 or 4".Does the ground strap for the alternator, disconnect from the frame or alternator, which is easiest? And do I need to remove the belt for the AC, as it is also keeping the housing from coming out any further.
I know this must sound pretty NOVICE, but we live out here in the sticks ...... no trustworthy mechanics.
Appreciate any help.
Please email responses to:
cooperokiehomie@cs.com

Thanks!
Gary

jet528e · 10-30-2003, 01:35 PM

Gary,
Just did mine for the first time on Monday. I have an '86, so it may be different than yours. You must take the AC belt off, otherwise you cannot slide the fan housing out far enough to unscrew the three nuts holding the alternator to the funnel-shaped air duct/guide (you will need to twist the entire unit to access the bottom nut). Once you remove the three nuts holding the air duct/guide to the alternator, you can disconnect the wires. I believe your car does have a ground strap and you'll need to disconnect that as well. Once all wires are disconnected, you can slide the fan housing and alternator out. Take your time as it is a bit tricky and frustrating as it does not slip right out. I found both these article very useful:

http://www.pelicanparts.com/techarticles/911_volt_reg_replace/911_volt_reg_replace.htm

http://www.pelicanparts.com/techarticles/911_alt_replace/911_alt_replace.htm

Good luck!

cowtown · 10-30-2003, 01:36 PM

AC belt: Yes, you should slide the AC compressor toward the fan housing so you can remove the AC belt before continuing.

Disconnect the ground strap wherever it is easiest for you to access. It may very well be hanging up on that strap, and until you get it off you might not be able to get the clearance you need to get to the other wires.

Get the tiny wrenches, think tiny thoughts and have a magnetic pickup tool ready! Good luck.

Colin

carreradpt · carreradpt's Garage

When I removed mine, there was very little room to get my hand back there to remove the alt wires. You don't want to put too much force on the wires. That is pretty normal. Take your time at this stage and don't break the vanes on the air guides. Then all you have to do is wiggle the fan/alt housing out slowly. Bead blast the fan after you get it out, it'll look much better when you get it back together.

ianz · 10-30-2003, 03:27 PM

Ya I just replaced the Alt on my 72T w/ AC

WHAT A PITA!!!!!!!!

The !@#$#@% shop that rebuilt the engine put the ground stap on with the engine out of the car when it was easily accessable......

I had to cut the the strap to get the Alt out....Good thing I work for an electromechanical design company, so I found a whole reel of the ground strap material to scavenge from

to make matters worse, when I had the Alt rebuilt by a local shop, they reshimmed the Alt shaft to line up with the brushes which shortenned the threads on the shaft for the pully nut to engage. I had to take it back apart and back down to the shop...

This was on top of dropping those pesky little 10mm nuts repeated, etc, etc......

but I finally got it back together, and happy again, and it all started with the dreaded dim charge light....

good luck with yours, the pelican how to did help out ALOT BTW

GC 53 · GC 53's Garage

Another Question.Where do you get the shims for the pulley? There were only 2 or maybe 3 shims where they say there is 6.
Does Pelican carry these?
You guys have been really GREAT. Thank you all for the help and experiences you had with your alternators.
Will be back on it this weekend.We're building a new house and it's keeping us jumpin'.
Gary

carreradpt · carreradpt's Garage

http://www.pelicanparts.com/catalog/shopcart/911M/por_911M_enginD_main.htm

Look under pulley shims.

carreradpt · carreradpt's Garage

Gary, just had to include these. You'll recognise the first one right off.

GC 53 · GC 53's Garage

Dan.......Thank you for the pics!! Everything helps.
Porsche Folks are the BEST!
Gary

GC 53 · GC 53's Garage

Is the ground strap the same one that goes across underneath of the tranny?
Also didn't see the shims on the pelican link.
Thanks!
GC

ianz · 10-31-2003, 06:33 AM

The ground strap goes from one of the alternator housing studs (that fasten it to the fan housing note: see the pic above, there are 6 studs) down to one of the studs on the engine crank case split line. (at least on my 72 anyway)

tsuter · 10-31-2003, 07:59 AM

78s didn't have a ground strap unless someone updated it. The alternator is grounded through contact with the fan housing and the housing with the motor. So don't powder coat the inside ring on the fan housing and sand off the bottom where it sits before reinstall. Or add a ground strap.

carreradpt · carreradpt's Garage

Shims are under engine miscellaneous, p.3 fans etc just scroll down you'll see it.