Crap, I broke my fan.

[maxman]

Alright,

Well my first project didn't end so well. My goal was the remove the fan and the fan housing for powder coat. I was armed with some very good instructions from another thread. The whole thing went pretty well, except for trying to get the main 24mm nut off of the alternator. I tried to do this early on, but the alternator shaft just spins. I tried to brace the fan by hand, with no luck. I then tried something really really stupid. I slipped a wrench through one of blades against one of the air flow wings in the behind the fan. I then tried to remove the bolt, after giving it some force it did not come lose. I didn't even notice that I had broken a section out of the back of one the blades. What a bad idea. I decided to worry about it later and get the whole assembly out. One I had it out, I tried my technique again unaware of my previously inflicted damage. This time I wrapped the wrench in a rag. I applied force again and heard a snap, this time I saw what I had done, and noticed the damaged from before. Crap! Here are some photos of the two blade that I damaged, they are nearly 180 degrees from each other.





Do I need to replace the fan, or is this livable? From a visual standpoint, I think once its powder-coated and all back together, you would have to work pretty hard to see the damage, but I'm worried about throwing off the balance. Like I said, the chips are 180 degrees from each other, that would help with the balance issue.

Now that I know once sure-fire wire to NOT get the alt nut off. What's the right way? I'm starting to think there is a tool I'm missing.

Feel free to shame me, I deserve it. Anybody have a fan they are looking to get rid of? Has anyone else done this? Should I just get over it?

~Max

[stormmaster]

I would replace it....it will cause a vibration due to imbalance that will cause stress to the shroud....fans are easy to come by...shrouds are not...I had to buy both....not a cheap solution.

[paulgtr]

I'm sure it could send stress back to the crank as well.

[cgarr]

Smooth up the broken edges and remove the same amount from the opposite side.

[maxman]

cgarr,

Have you done this before? What would be the best way to remove more?

[McLovin]

a dremel or grinder.

[maxman]

Is it worth the risk?

I'm seeing fans for as cheap as $300.

[steely]

Hi Max,

stiff upper lad.

Do you have one of these spanner wrenches?
It holds the pulley from rotating as you get on the 24mm fan nut.
Looks unimpressive, but you'll need it.
There should be one hiding in your tool kit that came with the car.
Otherwise available for something like $15.



(this is the right-hand model {kidding})

Good luck with the fan. +1 one the dremmel, not sure how'd you go about trying to balance.
See if you can get it running with the one you have, but maybe purchase one just in case.

on edit - What year is your car (suggest sticking it in your signature block)?
I found one for 250 - if I name the place they strike it out here (dcauto).
Look around - there are plastic ones too - don't know from price.

[Mitch Leland]

Max,

some things you can "paint over" and get away with... This is not one of them. Man up and replace the fan.

[maxman]

That's what I'm thinking... Not too expensive of a lesson.

[paulgtr]

yeah, you can just see in a month or two a car needing a rebuild from damage caused from an out of balance fan. an engine rebuild is 10 grand... instead of a 300 dollar part.... hmmm

[McLovin]

I don't think the fan is going to lead to an engine rebuild, the chips aren't going to affect cooling much.

It could lead to the alternator bearings going out prematurely, I guess.

There are a lot of 911s running around with chipped fans.

But, me personally, it would bug me and I'd replace it.

[rusnak]

Jeezus, man! Do not break the fan shroud. It is made out of very poor cast magnesium, and if it's from a 3.2 it is N-L-A.

[efhughes3]

Originally Posted by McLovin

I don't think the fan is going to lead to an engine rebuild, the chips aren't going to affect cooling much.

It could lead to the alternator bearings going out prematurely, I guess.

There are a lot of 911s running around with chipped fans.

But, me personally, it would bug me and I'd replace it.

That is well beyond "chipped" and not a good situation.

[maxman]

I'll replace the fan. Lesson learned. Thanks steely, I had that pulley wrench in the toolkit, can't believe I didn't think to look for it. You live and you learn, right?

[wdfifteen]

Originally Posted by McLovin

I don't think the fan is going to lead to an engine rebuild, the chips aren't going to affect cooling much.

It could lead to the alternator bearings going out prematurely, I guess.

There are a lot of 911s running around with chipped fans.

But, me personally, it would bug me and I'd replace it.

It could also have cracks that aren't obvious. Fans in general are infamous for high frequency vibrations that can cause fatigue cracks to propagate from the cracks caused by the damage. You don't want the thing to come completely apart on you.

[TimT]

Fans in general are infamous for high frequency vibrations that can cause fatigue cracks to propagate from the cracks caused by the damage. You don't want the thing to come completely apart on you.

Propellers= Fans? airplane propellers, boat propellers, ducted fans? jet engine fans? is there a propensity of failures that I have been missing?

How many of you have ever seen a 911 fan fail? "come apart completely"? I have never seen a 911 fan grenade.... and have some engines that we shift at over 9K

Having said that.. I am in the replace the fan camp, though I would re-balance it and use it until a replacement is on hand, as Cgarr mentioned

I'm sure it could send stress back to the crank as well.

This is very interesting... of course you cant push a string

[rusnak]

There was a guy on another forum who had his fan come apart completely. I was pressing for verification that it was the fan and not in fact the fan shroud that failed. Sure enough, the fan was destroyed, and a rectangular piece of the shroud was missing, but the center hub that holds the alternator looked ok.

So, I think the fan can crack, and it can come apart, albeit rarely. We know that alternator bearings can fail, and we know that the fan shroud is prone to cracking and can't be easily welded.

[efhughes3]

I've seen pics in the last few months of 2 cars that had pretty decent damage to their rear lids from fans coming apart.

We'rv started seeing Fuchs not lasting forever the last couple of years, I gotta believe that with no regular inspection by most 911 owners and some of these getting a bit long in the tooth, we may hear of more failures.

[paulgtr]

of course you cant push a string

true, but the fan belt is under tension. I would rather park and get a new fan than take any chances