Alternator Problems

I've got a few problems with my alternator removal.

1. I pulled the alternator per my Bentley manual. I'm trying to remove the alternator from the fan housing, but the picture in the manual doesn't match my alternator. I can't see anything that I can unbolt to remove the alternator from the housing.

2. Manual says to pull the fan off of the shaft using a "puller". What kind of puller?

3. Noticed that one of the fan blades has a nice chunk out of it. About 3/8 x 3/4 of an inch. Could this be causing the high pitched whine I have?

4. My alternator says that it is a Marchal with an external regulator. Factory tech notice says that this should be replaced with a new version (Bosch I believe), with an internal regulator. How do I do this? Do I really need to do this if I can get my current alternator fixed (if it's actually bad)?

Sorry for the long post, but I could use some advice.

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Bill Krause
'79 911SC Euro


[This message has been edited by wckrause (edited 04-11-2001).]

There is a couple of arrticles in the Pelican Tech articles on how to remove your altenator.I removed mine last week by using a hammer on the stud bolts that you tool the nuts off before you removed the altenator wires.Be careful, by hammering on the studs you stand a chance of mushrooming the heads of the studs.put the nuts back on the 6 studs and use a hammer on the nuts.Take your time and the shroud will eventually come off.
oh, yea.... If your fan is damaged replace it now.You don not want to go thru this again!

[This message has been edited by chuckr (edited 04-11-2001).]

chuckr -- I got the alternator out and the fan off. Rather than hammer on the stud bolts, I used a small piece of wood and tapped on the case of the alternator. It eventually came out. Did the same thing to the fan.

I am going to take the alternator into a local shop and see if they can rebuild it. The bearings on it sound a little ruff, and may be the cause of my excessive whine.

New fans are about $250!!! There are a lot of boat shops around here that can weld up aluminum propellers, maybe I'll see what they can do with this fan.



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Bill Krause
'79 911SC Euro

the best way to get an alternator out of the housing is to use inertia. fold a couple of shop rags and place them on the floor as a pad.take the housing/alt/fan unit in both hands, with the fan facing down, and firmly bop the edge of the housing on the rags. you would hold it on an angle to do this. turn it and do the opposite side. repeat as necc. it will come right out, no hammering or abuse. to remove the fan, keep the rags on the floor, position the alt over the rags, hold it off the floor with one hand holding the fan and the opposite side of the fan supported by your boot. bip the shaft with a heavy plastic, shot filled mallet. repetedly. this gets most of them off. the rest get the airhammer treatment with a pointed bit. centerpunch the shaft to keep the bit centered, and run it thru. no thread damage. don't hit it with a metal hammer!

[This message has been edited by john walker's workshop (edited 04-11-2001).]

[This message has been edited by john walker's workshop (edited 04-12-2001).]

I looked over Porsche Technical Bulletin 1, in my Parts and Technical Reference Catalogue (under $10), and I'd get the alternator rebuilt too, if I were you. It looks like the updated unit takes a different, or modified air duct.

A local alternator shop should be able to rebuild it, as long as the windings are still good. Certainly they can replace the bearings and brushes.

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'83 SC

Bill: I'm wondering if the chunk out of your fan will cause it to become unbalanced. I suppose that depends on the weight of the missing piece. If it is now unbalanced, you may end up ruining bearings in your alternator, once reassembled. Surely you can find a used one.
regards,
jlex.

That's a good point. I'm going to look into getting it repaired, and if that's impossible, I'll look for a used one. Along with the big missing chunk, there are a couple of smaller chunks gone. All on the trailing edge (thinnest section) of the blades.

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Bill Krause
'79 911SC Euro

My fan makes a high pitched whine but when I removed it to paint the fan/housing, the alternator spun smoothly. It is just over a year old and as far as I know has always been tensioned correctly.
I am just going to keep an eye/ear on it and monitor it and the warning light!.
I wish I had known how relatively easy it was to remove as I would not have paid my original thief/ i mean mechanic, to put a 'new' one on! (cost around $400!!! plus labor! )
Good point is to check the state of your battery and that it has not boiled over in the meantime and risked the dreaded rust around it (very costly!)
....It's all a learning curve!
Good advice, if you find a good/trustworthy wrench, hang on to him!!!
rgds Ben

Bill:

My alt was replaced by the PO with a later unit with an internal regulator (which reads "Valeo 14v 75amp A14 N 11 PORSCHE 911 603 120 04 J O"). I purchased a new battery and had the alt rebuilt about the same time.

You want to check the commutator against which the brushes push for wear. If the shop you take it to says "we can turn down your commutator and put new brushes in, but this is the last time it can be done on this unit" then I would spring for the updated alt. and use the old one as core/exchange. I suggest this because of the pain it is to remove this little puppy. Might as well spring for a new one than put one in that is on its last legs.

Jw

Jdub,

Did you have to mod the air duct to get the internal regulator to fit? Are there also some wiring changes when switching from an external to internal regulator?



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Bill Krause
'79 911SC Euro

the original black wire is not used. it went to the brushes on the old unit. make sure you remove the old regulator so someone doesn't plug it in again. you do have to notch the fiberglass piece that bolts to the back of the alternator, to clear the regulator. i use an air hacksaw, but snips will do it.

[This message has been edited by john walker's workshop (edited 04-12-2001).]

Bill:

This was done prior to my purchasing the car so, alas, I cannot comment on what modifications were required to put in the later reg-in-alt unit. However, it really doesn't look different, shroud-wise, from the other '78s I've poked around in.

And my car also does not have the old outside-the-alt regulator in place anymore, as JWalker has described.

Please let me know if there is anything I can look at in my car that might help you gain some knowledge on what you need to do. I will make a point of examining the shroud and other areas against photos to determine if hacksaws or otherwise were used to put in the later unit.

Jw

I took the alternator into the shop, and they're going to test it and give me the results. If it tests OK, or if it's rebuildable, then I'll put it back in and stay with the external regulator.

Now I just need to figure out what to do about the messed up fan.

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Bill Krause
'79 911SC Euro

Is the fan made of Magnesium?
If so, forget about the "Boat Shop".


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Doug
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
members.home.net/zielke/911SC.htm

Went throught this ordeal with a 78SC several months ago.

1. Fan -- On 78 model, and I believe 79 model, fan diameter size is smaller than 80 on, even though all fans of that era are 11 blade. This results in difficulty obtaining new or replacement fan of this smaller diameter size. What I did was change to larger fan housing and accompanying fan used in carrera. Bruce Abbott provided this very useful information regarding interchangeability of fan housings.

2. Internal regulator v. external. If you change over to the internal regulator, you will need to either modify or replace the air duct which, on the internal regulator models, has a cut out in the shroud to accomodate the physical configuration of the regulator. New shroud is approximately $100. The Parts and Technical reference catalogue has the technical update which details the conversion in step by step process. I stayed with external set up.

Good luck

The fan is magnesium. I found a shop that might be able to work on it, but I'm not optimistic.

Does the Carrera fan housing still fit with the SC fan shroud?

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Bill Krause
'79 911SC Euro