Novice question about the alternator belt

[piscator]

Steve,

You and I can be confused together! Here is the PET diagram taken from the Porsche Classic website. Unless my eyes deceive me, there is no 'spacer' behind the fan.

Porsche calls the 'spacer' a 'tensioning cap' and lists the parts shown as follows:

6 = fan
7 = shim(s)
8 = pulley
9 = tensioning cap
11 = hexagon nut

Oddly, they don't show or list the woodruff key (half-moon shaped thing) that fits in the groove in the shaft and secures the fan. Steve, that woodruff key is behind the fan, which is why you can't see it.

Lee and John, what am I missing?

[john walker's workshop]

The spacer comes on the alternator, along with the key. It's an assembled unit. If there was an exploded view of the alternator, you would see it. If it isn't in place, the fan would go onto the shaft too far and contact the alternator housing, which is the case here.

[john walker's workshop]

You can see it in place here. Disregard the split lock washer hanging on the shaft. They come with the rebuilts for some reason, but they are not used.

[steve meltzer]

Yes, Smadsen, I'm grateful to all of you who have taken my seemingly straightforward question so seriously. Has sparked (ooooh....great pun) a bit of a debate, as the drawings seem to be at odds with the clear photos provided by Lee and John Walker.
On my way to the garage after I get a sip or two of coffee. Will report back, but I'll bet my fan is jammed against my alternator, as suggested by John Walker. steve

[piscator]

Steve,

I don't think John has made an incorrect statement in the ten years I've been here! One of John's early threads on shifters is what got me started on Pelican. To me (and everyone else) John's help has been immeasurable. Thanks John!

I went looking for a PET alternator diagram but couldn't find one. That photo's a big help, but I'd still like to see both sides of that 'spacer.' Is it flanged like the tensioning cap or just a big, thick, symetrical washer?

[boyt911sc]

Originally Posted by piscator

Steve,

You and I can be confused together! Here is the PET diagram taken from the Porsche Classic website. Unless my eyes deceive me, there is no 'spacer' behind the fan.

Porsche calls the 'spacer' a 'tensioning cap' and lists the parts shown as follows:

6 = fan
7 = shim(s)
8 = pulley
9 = tensioning cap
11 = hexagon nut

Oddly, they don't show or list the woodruff key (half-moon shaped thing) that fits in the groove in the shaft and secures the fan. Steve, that woodruff key is behind the fan, which is why you can't see it.

Lee and John, what am I missing?

Robert,

You are giving a poorly conceived advise based from a totally different PET. Go and check your alternator. Behind the fan are the alternator spacer and the woodruff key. These are integral parts of a complete 911 alternator. Refer to the picture JW has attached.

Tony

[Leebag]

Originally Posted by steve meltzer

@Leebag...is the spacer you show, the same as the middle "shiny" piece i have in the middle of the array i posted to start this thread? thanx steve

It looks like it. This spacer is located in front of the bearing in my alternator on my 83 sc. I’m not an expert, I don’t remember if the spacer is installed reverse on my previous image I posted. Your orientation of the spacer maybe different than mine. Other expert members can chime in.

[brcorp]

Did you get a key?? If not you're done. A spare is a must have! Also if you're doing this on the car be careful not to drop any small parts down in the engine mount. Probably should pull the fan off to shaft to verify the spacer is in place. And finally, do a quick assembly without the fan belt to verify everything spins freely. Good luck!

Originally Posted by steve meltzer

Is the thick spacer that "shiny piece"? I have no key either. argghhh. thanx steve

[HarryD]

I looked at my 1973 PET and found in Main Group 1 105 Air Cooling
the following illustration:



Note item 8, the woodruff key.

Looking in main Group 9 901: alternator distributor, I found the following Illustration:



Note the Items on the second row. After the rear facing housing, you see a spacer, woodruff key, spacer and a nut. It appears these items are behind the blower fan.

[Leebag]

Originally Posted by john walker's workshop

You can see it in place here. Disregard the split lock washer hanging on the shaft. They come with the rebuilts for some reason, but they are not used.

Thanks for the info regarding the split washer. I thought I have to use it since it was included with the rebuilt. Op thanks for starting this thread.

[steve meltzer]

OK, i had a misstep, but I understand now how this works. I knew i had to tear it down and start over, so I loosened the battery quick disconnect, buy apparently not completely, as during the disassembly i got a big spark (and scare!) just after I removed the ground and warning light wires. I must have tilted the alternator to a ground while it was still getting juice.

Once the alternator was on the bench, I was lucky enough to find the Woodruff key laying below the lower (crank) pulley. That "shiny" concentric piece went in as John W. and Lee said it would, and the whole unit went back in the car without too much of a fight, other than that $%**## air guide, POS.

With the washer against the alternator bearing, Woodruff key in place, it took 2 shims in and 4 out to get proper belt tension. However, despite all of this, with fan and belt turning, it isn't charging...as noted by the warning light staying on and the VOM showing the battery DISCHARGING, NOT CHARGING. True even when revved up. I think the spark was a warning that i either damaged the VR or the alternator itself. Confident it is wired correctly. But I've also posted the wiring as viewed on the back of the alternator. The red paint blob is the positive terminal. BTW: I checked the fuses and they are all fine.

thanx steve

[Leebag]

Steve
Hard to tell with the red paint. Double check your + and - at the back of alternator. See if you can find any marks ? Mine is reverse.

[steve meltzer]

Under that mess of red paint (no Picasso, here) there's (+) sign, and that terminal is bigger than the others. Thanx again, Lee. steve

[Leebag]

Originally Posted by steve meltzer

Under that mess of red paint (no Picasso, here) there's (+) sign, and that terminal is bigger than the others. Thanx again, Lee. steve

My mistake. You’re correct.

[steve meltzer]

After screwing up so much of this project, I'm glad to have gotten at least the terminal correct. Leebag, thanx again for all of your good help. steve