Alternator Replacement - NEED HELP!

NorthGaRob · 02-20-2011, 10:23 AM

I finally got the parts I needed, including the missing fan shroud that goes on the back of the alternator. It's a 1983 911SC.

But now that I am trying to get it all back together I am having some real problems getting the fan to spin without grinding.

When I get the alternator, fan, and fan housing all together it spins fine. But then I hooked up the wires and as soon as I tighten down the nuts that hold the fan shroud on - which presumably tightens up the fan to the fan housing - I get some grinding.

A couple of thoughts...

If I put the 6 nuts on the fan housing (on to the 6 bolts of the alternator), I have to really finesse and adjust them just right to keep the fan from grinding, and when it is grinding I can see that it is the ends of the fan blades on one side. Tighten the opposite side and the fan will spin freely. I can get them on with some work in a balanced way that ends up letting the fan spin freely but it does take some work.

But, those nuts need to stay off until I get it in there and get that (new to my car) shroud on the back of the alternator. Once I tighten those nuts down, I am back to grinding.

There are a couple of cracks in the fan housing and I am wondering if those are making it uneven, causing my problems.

I am starting to wonder if that is the reason that the shroud was missing in the first place: perhaps a previous owner had the same problem and left that shroud off because of it.

I really need to get this car running ASAP, so any advice would be massively appreciated. Including opinions as to whether I can go ahead and leave that fan shroud off, which would allow me to more effectively get that fan spinning freely without messing that balance up by tightening up those nuts with the housing almost installed, as you have to do to get the wires connected and the shroud on.

Thanks very much in advance for sharing your opinions and expertise.

Rob
1983 911SC

bsimonson · bsimonson's Garage

Hi Rob, I'm not sure this is your problem but are you sure you refitted the washer that goes between the alternator and the fan, on the inside of the woodruff key?

Good luck!

/Björn

NorthGaRob · 02-20-2011, 11:58 AM

Thanks for the reply, Bjorn!

I had initially forgotten that washer and had that grinding as a result. Once I got that washer on there, I thought that I was home free until I tightened up the nuts on the air deflector that covers the back of the alternator and the fan would not even turn.

I have some decent cracks in my fan housing and I am worried that this is my problem.

Does anyone know if a good metal worker could fix cracks in the housing?

Thanks for any input,

Rob
1983 911SC

NorthGaRob · 02-20-2011, 12:25 PM

Of course, any fix would require getting it all back in line, which would be the hard part.

I see that one website is selling new aluminum housings. Does anyone have any experience with those?

RoninLB · 02-20-2011, 02:48 PM

Quote:

Originally Posted by NorthGaRob

, I have to really finesse and adjust them just right to keep the fan from grinding,

But, those nuts need to stay off until I get it in there and get that (new to my car) shroud on the back of the alternator. Once I tighten those nuts down, I am back to grinding.

There are a couple of cracks in the fan housing and I am wondering if those are

i have no cracks anywhere and need to "finesse" the nuts after doing the wiring

NorthGaRob · 02-20-2011, 02:54 PM

So your fan rubs against the housing as well even though you do not have cracks? But playing around with tightening them (and maybe loosening some to compensate?) gets you going?

RoninLB · 02-20-2011, 03:04 PM

Quote:

Originally Posted by NorthGaRob

So your fan rubs against the housing as well even though you do not have cracks? But playing around with tightening them (and maybe loosening some to compensate?) gets you going?

yes

but i never loosen them for correcting the fan. I just go slow and make sure to not over torque the nuts or the plastic air deflector is likely to crush or crack. I actually torque to just very snug, not tight. I've never had a nut come loose

I start all the nuts so i can adjust the fan by spinning it and try to keep it in place

i also use never seize

no big deal as long as you have patience

steely · 03:09 PM

Does it grind before you put the belt on?
I hate to say it friend, but I don't like the cracks at all.
Not sure if mag can be welded.
Is it possible to weld the alternator fan housing?

Flat6pac · 02-20-2011, 03:23 PM

The easiest way is to cut 3 of the extension 6 retainer section and pull the alternator tight to the housing with 3 nuts and washers.
Spin the fan and install the wires and extension and bolt it up with the remaining 3 nut places.
The first 3 locate the alternator solid so the last 3 nuts will hold the extension on but not effect the centering of the fan.
Bruce

RoninLB · 02-20-2011, 05:26 PM

nice

ghnat · ghnat's Garage

From your pic it looks like the fan was rubbing already - see left side of the housing in the pic.
With those cracks I would say a new housing would be a safe bet. You could try the 911 used parts here and post a WTB (Want To Buy). Someone should have one up for sale or might be willing to part with one.

Flat6pac · 02-20-2011, 05:42 PM

Theyre most all bad, especially when you get in to the 84 up. Big alternator with lots of tension on the belt, something has to go....I like the aftermarket aluminum one sets up well and very strong.
Bruce

Tom Macy · 02-20-2011, 05:48 PM

Did you drop your fan? If so it is probably a gonner. Alittle outofwhack you can't stop the off beat sounds.
Tom
88 carrera targa

NorthGaRob · 02-26-2011, 03:26 AM

Thanks for all of your help. I picked up a fan housing from a very helpful PP member and got it all together last night. I have to drive up into the North GA mountains today and will give it a good test.