Alternator Fan Shroud Too Big??

[ErikT]

I am having a hell of a time replacing this alternator.

When I took the bad one out a few weeks ago, I noticed that the circular fan shroud was cracked in several places. Putting the new alternator and fan in I noticed that it did not spin freely and was warped.

Checking the web for a new circular fan shroud, I was dismayed to find a new one costing almost $600, at PP.

I ordered a "new one" from a different vendor for half the price. I appeared to be the same as mine, except that it had 2 bolts coming out of it. My 86 Carrera does not have those bolts.

Looking at the old shroud, it was clear that someone removed the bolts from that one....so I Dremmel tool cut off the two bolts.

I am having one HELL of a time getting this damn thing in place.

Is there a secret to this? I put the bottom half of the shroud inside the pulley....and then the top will not go in.... and vice versa.

The alternator is wired. All I want to do is put the fu-kin thing in place and put the belt on...but it wont apparently fit.

The "New shroud" measures just over 11 inches in diameter.... the "old shroud" measures just under 11 inches in diameter... help.


** Also...the metal clamp thing that fits over the alternator will not fit down... the bolt will not meet the two together....

I think this thing may be too ****in big...anyone have the exact dimensions that the fan shroud should be??

[Grady Clay]

Eric,

Step back and take a deep breath. Sit down with your favorite beverage and relax.

What year is your 911? Is the engine original? What do you know about past history?

Some nomenclature:
Fan shroud is the fiberglass part that covers the entire top pert of the engine.
Fan housing is the alloy supporting structure for the alternator and fan.

It will all work out just fine.

Best,
Grady

[ErikT]

86 Carrera, looks like the alternator had been replaced before. The fan housing has been scrapped and nicked all over as well as cracked.

The new fan housing appears to be too large for the mounting space. I was able to finally jam it in there...but now the edge of the fan housing rests atop of the inside pulley.

The mounting screw (screws the metal plate over the fan housing to secure it) is now too short.

I am on my way to the hardware store to look for 1) a longer allen-head screw to use to secure the fan. 2) a metal nail file to reduce the lower edge of the fan housing so that it will not hit onto the inside pulley.

[Grady Clay]

Whoa Haus,

There is a roll pin in the case that locates the fan housing. Are you certain I the fan housing is properly positioned and seated?

One thing about Porsche parts is they always fit. The parts in your engine are the best in the world. I have never seen a Factory Porsche part that had to be “worked” in order to fit. Yes, we all take parts and mod them for all sorts of unintended purposes. That is not your issue. If you have the right part, it should fit.

Perhaps you have the wrong part?

Who else can shed some light here?

Best,
Grady

[ErikT]

Grady... I lined up the fan housing with the 2 bolt holes on the top of the fiberglass piece. This is where the "tie downs" for the sparkplug cables go. That part of it lines up.

As I mentioned, this fan housing was a bit large and I had to "wedge it in there in order to get it to fit...with a breaker bar.

As it sits now, it appears to finally be situated correctly.

Here's something interesting: Looking at the old fan housing, there was a groove cut in the bottom by the pulley previously. Apparently at one time or another, the pulley hit on the housing and ground it down.

THIS is what I am trying to avoid now, by slightly filing down that area so that the pulley does not hit on the fan housing, hence the trip to the store to get a metal file.

I agree with you that everything should fit up right...and at this point with a ton of effort, it appears to have done so.

But every car is different. For example on my car, it was a PITA to take the AC belt off because the compressor would only shift so far to the left, even when removing bolts.

After I get this thing in place, I will put the pulley and belts on. Hopefully it will work...if not, I will have it towed to the garage.

[masraum]

Originally posted by ErikT


The new fan housing appears to be too large for the mounting space. I was able to finally jam it in there...but now the edge of the fan housing rests atop of the inside pulley.

The mounting screw (screws the metal plate over the fan housing to secure it) is now too short.

I am on my way to the hardware store to look for 1) a longer allen-head screw to use to secure the fan. 2) a metal nail file to reduce the lower edge of the fan housing so that it will not hit onto the inside pulley.

Erik,

I've replaced the fan and housing on my old '88. There should be no problem with the housing. As Grady says, if you have to modify anything to get it to fit then you either have the wrong parts or you are overlooking some small detail. This can be a paint to put in, but it shouldn't be too bad.

If the shroud is touching the lower pully then it shoud be able to be moved back some. Do you have a digital camera or is there one that you can borrow? Where are you located. There's a very good chance that there's a Pelican nearby that can take a look at this with you to keep you from possibly causing any problems to your new expensive housing.

After you've removed the housing and you are trying to put the fan strap back on it can be a REAL bear to get the bolt started in the fan strap, but it's not too short, just really difficult. Do you have a large pair of channellocks or an extra set of strong hands? That's what you really need is an extra set of hands and eyes.

Don't cut or file anything else without getting someone else to look this over with you. How pissed would you be if you changed something on the new part and then found out that it caused a problem and you had buy another new one?

Like Grady said, these parts are precision made, and stuff that fits that closely can sometimes be difficult to get back together correctly, but it will go.

[masraum]

Originally posted by ErikT


Here's something interesting: Looking at the old fan housing, there was a groove cut in the bottom by the pulley previously. Apparently at one time or another, the pulley hit on the housing and ground it down.

THIS is what I am trying to avoid now, by slightly filing down that area so that the pulley does not hit on the fan housing, hence the trip to the store to get a metal file.

The pulley should have a small indentation at the bottom in a cresent shape where the pulley is with a small vertical line in it. Are you sure the thing you are looking at isn't what's supposed to be there?

[masraum]

Look in this picture at 7 o'clock. You can barely see the indentation in the fan housing where the pulley is and the mark that gets lined up with the pulley, that "groove" is supposed to be there.

[ErikT]

Thanks for the Pic Steve.

The fan housing that I purchased...does not have that "groove" cut into the bottom.

The old fan housing DOES have this groove...but it also has a mark on it where the pulley had obviously been rubbing against it at one time or another.

Below is a pic of the New housing that I purchased (note, I cut off those bolts on the outside because they werent needed on my Carrera. You cant tell here because its on the wrong side, but there is no groove on bottom on the other side.


Below that is a pic which I took of my old fan housing...note the groove and the pulley-wear mark.







I tried using channel locks on the strap bolt but it still is a bit short. I picked up 2 longer 8mm cap socket bolts from the hardware store which should work.

[masraum]

I bought a new housing for my fan from a dealer, and have seen the same that someone purchased from Pelican. They were both genuine Porsche parts and came with a matte black coating. Mine matched what I took out.

Maybe the reason the part was so cheap from the other vendor was either because it was aftermarket or the wrong part for the wrong year. That might explain the problem with fitment.

[silverc4s]

There is an early (pre mag case) fan housing / fan assembly that is NOT compatible with later car hardware. Don't ask me how I learned this...
It is a cast aluminum housing, NOT magnesium, and it is a couple of cm larger in diameter, requiring a special fan as well. Perhaps someone sold you one of these housings. If so you should be able to swap even with an early car restorer for the housing you need, as these are now pretty rare, I believe...
Good luck, don't destroy the one you have making it fit, only to find a simpler solution.
PS In your picture it DOES look like aluminum to me..

[ErikT]

It doesnt feel like aluminum...it feels like magnesium.

The part is stamped with the other vendors name at the top. Obviously, they are remanufacturing old ones.

The fan fits fine... the part is slightly larger. The only problem at this point is that it doesnt have the groove at the bottom that the old one does. Im working on this now.

The bolts at the top were used for the pre-Carrera cars...see Waynes rebuild book. maybe this was for a 2.7, SC or something.