What would seem cause alt. pulley nut to hold tight, but the pulley slides around????
 

What would seem to cause the alternator pulley nut to hold tight and will not loosen, yet the outer pulley half slides around as if it's loose????

Maybe the wrong number of shims. Should be 6..some go under the pulley, some go over. The exact number will create the tension you want. If you use less than you have, the "unused" ones go under the nut on the outside of the pulley. If you run NO shims ( or fewer than 6 in any combo of under/over the pulley), then the bolt will bottom out and the pulley half will rattle around.
--Wil Ferch

I think Wil has found your problem, not enough shims under the nut. I vaguely remember reading, somewhere, that some (perhaps earlier?) models used 7 shims. I'd try putting one more shim under the nut and washer. May as well put on a new belt too, cheap insurance if yours has been slipping and may have glazed one side.

Jerry M
'78 SC

It appears that under the washer and nut I have only one shim. :mad:

I assume therefore that the nut always stops at the same spot, and therefore the nut is tight. But with only one shim under the outer pulley they both (outer pulley and one shim) slide :mad:

But are there 5 others behind the outer disk that the belt rides on for a total of 6? If not, then you need to get whatever is needed for a total of 6. You will need all 6 to get it tight. Six is key. What torgue setting are you using? It is supposed to be 29lbs.

You really must determine how many shims you have between the pulley halves and under the nut. They must total 6 (or perhaps 7, I'm still not sure about the earlier models). To adjust tension on the belt you move shims from between the pulley halves to under the nut (or vice versa). If there are too few shims, tightening the nut will run it down to the end of the threaded portion of the shaft and it will appear tight but the pulley half will still be too loose. Unfortunately when someone does this (forgets a shim), they then, noticing the belt is slipping, try to re-tighten the nut even more which just causes it to seize at the end of the threads. If this should happen, removing the nut can be very difficult.

Jerry M
'78 SC

There's a good description of the belt replacing/tightening procedure HERE . Be sure to read the whole article. Charlie gives a good expanation of the use of the shims.

Jerry M
'78 SC

H.G.P.

I see you have another thread here, asking how to remove the seized pulley nut. I don't think you'll be able to hold the pulley with a pin-spanner and get enough force on the nut to remove it. If I were in your position, I think I'd try a chain-wrench (used by plumbers on large pipe) to hold the inner pulley (you may have to cut the belt off to get the wrench on) and fabricate some way (stack some type of blocking under the handle?) to hold the chain-wrench while you use a large breaker bar and socket to remove the nut. No amount of PB Blaster is going to help because the nut isn't corroded it's actually jammed onto the non-threaded portion of the alternator shaft. It will take a considerable amount of force to back it off, but it can be done if you can hold the pulley. I'm afraid you may have to buy a new pulley after all this, the outer half is probably damaged already.

Jerry M
'78 SC

My outer pulley with the holes, slides around easily and I can slide it by hand.

The holes after driving, the holes in the pulley(the ones used for tightening wrench) are almost never matched up with the inner holes on the alternator facing. I think I'm hearing the rattle getting louder. So I think I better stop driving until I can get that frozen nut off!

Should I use a nut splitter ?, and then just go buy the correct mm. replacement nut? I'm concerned that I may damage the nut axle itself or worse by using a tool in the holes. I have the pulley tool but it isn't working...it bends when tring to wrench the nut.

Thanks for the replies, and the article reference.

If you can't get it off, you may ned to replace it any way.

I would think about cutting the belt and removing the alternator so you can work on it on the bench. You may find a way to lock the shaft so you can turn the nut or get a dremel on the nut to cut it off without getting the threads.

Over 50 miles from what I understand is the nearest Porsche shop. So I think I may have to do this myself. (as I have had to do everything so far). I hope after I'm done with this the rattle isn't a timing chain or something , but I can slide the pulley by hand and hear it clang-ring .

I'm afraid to take it to a general sportscar specialty shop, as I don't want the blades broken by accident.

I've never removed an alternator on a 911 (have on a Buick), so I think I'm going to have to try to split the nut without damaging the threads. Any pointers appreciated.

I assume these are all 22 mm nuts (as stated in the article), and can be obtained at most hardware outlets. As for shims? If I need a pulley, I call Pelican.

Thanks

It is not hard to remove the alternator. If you haven't already, get Wayne's 101 projects, one of them is to rebuild your alternator. It gives the instructions there.

My car has a 24 mm nut so you may need to take the alternator with you. You will also need the shims so you may want to order the whole shooting match at one time.

H.G.P:
I happen to have an article in the Tech Section on alternator/voltage regulator repair and replace.....go look... it might give you some guidance :)

--Wil Ferch

Yes thanks....I went over the article and the pics, and I also have Wayne's 101 book. The alternator from all indications is working alright, it's that rattle and the outer pulley sliding I want to stop..........SO.....: I went to Lowes today:

1. Picked up a couple of nuts, in case I end up damaging the nut. But I won't be sure if they are even the right of size until I get (if I do) the nut off.

2. Am looking into purchasing an electric impact wrench by tomorrow, (maybe Walmart, Lowes, etc.,) if they have one. Do not even know if it will fit into the work space. (I do not want to remove the alternator)

3. I'm concerned about using a nut splitter/hack saw, as I'm not sure if I can find the proper WIDTH of the replacement nut from a hardware store, and I want to stay clear of the shaft threads.

4. Pelican list no pulley in my search , so hope it's not damaged. (the holes look ok,,,i.e. the pulley wrench fits in them)

So maybe last chance in an impact wrench.

The Pelican web site lists the shims (Part #s A-105-561-00/90110556100 ) for $1.10 each. The Pulley half (A-603-421-01/ 90160342101) for $18.60; and the nuts (N-011-163-3) for $1.40.

Removal of the alternator takes about 15 minutes, and is easier than a Buick.

Good luck.

H.G.P.

Read my post in your other thread... "For Lands SAKES! The pulley nut won't budge!"

May save you some time or at least give you some ideas.

Loose Pulley
 

I replied to your earlier thread, but will repeat some hard learned
info.
Be prepared for the pulley to be damaged...the hole may have
wallowed out so it is no longer a good fit...also, and worse...
if this has been going on for some time...the shaft on the
alternator will have been grooved....this happened to mine, but
I was installing a new alternator so that was not a problem, and
I had the pulley mig/tig welded so material was added and the
opening was restored to it's original dimentions. The six shims
are madatory...