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Posted by: kconway Mar 14 2011, 08:49 PM

How do you remove this without breaking it? I hear the mag is pretty fragile. I tried tapping on the "hub" from the backside but it didn't budge.

Kev

Posted by: PRS914-6 Mar 14 2011, 08:58 PM

Hold the assembly off the bench by holding on to the fan itself and have someone tap the alternator shaft with a brass hammer. The alternator and fan housing will fall out the back so make sure it doesn't land on the floor! If that fails, heat the hub around the shaft and repeat while hot

Posted by: kconway Mar 15 2011, 12:12 AM

Well, fans off...alternator is f'd up...I missed the part about using a brass hammer and had the wife "help" by "tapping" on the alternator shaft. Not sure she ever hit end of the shaft. After several glancing blows to the threads I've got an alternator that I can't start the nut on and a stripped nut from trying

I should have known better!

Anyone have a 911 alternator FS?

Kev

Posted by: mojorisen914 Mar 15 2011, 07:31 AM

I would think that you could find the right size tap to clean up the threads. Or maybe not. It would be worth a try; can't hurt it anymore than it is.

Posted by: SLITS Mar 15 2011, 08:39 AM

Kevin ..... flat file the mushroomed part of the shaft to size, then use a thread file (triangular file) to clean the starting threads for the nut or obtain a die the correct size / thread pitch. (I don't know what it is).

If you need another, I need to know what alternator you have. Bosch, SEV Marachal, Rhone Paris, Motorola ..... etc. There are a couple of different ones with different mounting depths.

Posted by: PRS914-6 Mar 15 2011, 08:56 AM

I'm sorry I didn't mention it's not a wife job I just assumed everyone knew that. Brass is essential around threads but I'll bet with a file or a Dremel you can repair them

Posted by: Cap'n Krusty Mar 15 2011, 09:00 AM

The shaft and its associated threads are too fragile even for a brass hammer. That goes for hitting it with the nut on it, for the most part.

The Cap'n

Posted by: kconway Mar 15 2011, 10:59 AM

I'll try to fix it up, I think I have a file that will do the trick. Damn threads are sooo fine on this thing, not sure I can find another nut. Oh yeah, the nuts f'd also from trying to restart the threads.

If I'm not successful, it is a SEV Marachal alternator.

Kev

Posted by: McMark Mar 15 2011, 11:33 AM

I'm not nearly as well-versed in six cylinder parts-n-pieces, but can't you unbolt the alternator and pull the fan/alternator unit out together? Seems like it would make it a lot easier to hold the fan...

Posted by: PRS914-6 Mar 15 2011, 11:53 AM

Yes and No.....The bolts that hold the alternator halves together go through the fan housing as well. On numerous occasions I have tried to unbolt them only to have the long bolts spin requiring to hold the bolt heads that are under the fan.

Normally it only takes a "tap" with a brass hammer since it's not an interference fit and I have never damaged a thread doing so. They normally slide right apart. However, that is why I mentioned heat if a "tap" didn't work. A little heat (oxy-acetylene)around the hub and you can usually lift it right out without anything.

Yes, a brass hammer can do damage if you don't use it right. In fact I can drive nails with one if I hit hard enough......However, a straight "tap" at a 90 deg angle should have done the trick with no damage at all...Done it many, many times. If it requires a "blow" than heat is a good method combined with a "tap"

You can also use a piece of hardwood on top of the shaft for more protection but get lesser results.

Posted by: kconway Mar 15 2011, 01:24 PM

The long bolts were difficult to remove as well. They would not fall out after i removed the nuts and had to apply quite a bit of torque to thread them out after the fan was removed.

No doubt this would have worked fine with a brass hammer and/or a block of wood, I just couldn't hold the fan and tap at the same time and needed help. My fault, I should have waited until I had another pair of hands to help out (besides the wife).

Kev

Posted by: Ericv1 Mar 15 2011, 03:46 PM

I just did this last night as my alternator failed. I tapped 2 of the 8 holes around the center of the fan and screwed in bolts. Then, I tightened the bolts until the fan popped off. I think I read this on Pelican a while back. It worked really well.