Question: Alternator pulley/nut removal?

strange, normally on the ferrari alts there is an allen key in the shaft. must have been replaced at some time during a rebuild with something else.

it's not left hand threaded is it?

otherwise the pulley should be key'd to the shaft normally, but with what looks non-oem to me I don't know if that's still there.

 

Put a screwdriver between the fan blades and then remove nut with a socket or offset wrench. Impact wrench works even better. The nut is not reverse threaded.

 

I would try the screwdriver only after holding the fan with a rag or towel and trying that first. I think the screwdriver risks bending the fan.

 

When I did mine I used penetrating oil, grabbed the fan with a thick wad of rag and used the impact wrench. Came off easily no damage to the parts and (equally important) my hands.

 

Impact wrench. Buy one, very useful on the car. Never used it on wheel nuts but many other places such as alternator.
Peter

 

Like Pero said, use a impact wrench. The easiest way and no damage to parts. Been doing this for 30 years and never had a problem.

 

Try using the old alternator belt, cinched tight, to hold the pulley after you've let the PB Blaster soak in overnight. And as everyone else has already said, use an impact wrench - the half-inch electrical that Harbor Freight sells is adequate for once-in-a-while use.

 

I have a cheapo Harbor Freight electric impact wrench and it works great. I bought it on sale for around $35.

1/2 in. Electric Impact Wrench

I have never had an issue with bending the cooling fins using a screwdriver. Some of the other methods (towel/belt) sound like good methods too.

Really consider getting an electric impact wrench. I have a quality pneumatic wrench also but use the cheapo electric one more and more due to convenience.

 

As ehamilton posted. Old belt pulled tight round pulley and held in vice. Then impact wrench or even socket/wrench on nut.

 

Thread hijack...
Does anyone know the correct size of the alternator pulley for the 81 GTSi? I bought a new belt, correct part number, and it seems to be too small for the WP/Alternator. Even with the alternator pulled back I cannot get it on. I compared it to another belt I had and it is slightly smaller. Is it possible that the previous owner put a larger size alternator pulley on? I had a belt already, but bought a new one as a spare.

 

By the way, use an impact wrench for the nut

 

Or a whole different alternator (other makes, with lower RPM engines, tend to use a larger alt belt pulley). What is the Gates PN for the (too short) belt that you bought - 7M975 or 7M1000?

 

I bought part #117435 from Superformance. I will check the actual part number tonight..

 

I change mine to a smaller pulley so even at lower RPM Alt. still spinning fast, no more dim light at idle speed.

 

Please do. I thought the carbed cars used the 975mm long belt and the 308i/308QV with the single WP+alt belt used the 1000mm long belt (so 107971) -- didn't know that there was/is a third possibility (AFP shows that 117435 PN as being 7M950 so it's shorter than both?: http://www.allferrariparts.com/117435.html).

 

The shaft on my 328 alternator had the allen key recess as described by smg2 but I didn't use that to remove the nut. Instead, I separated the front and rear case of the alternator. Then I took the pulley/front case/rotor unit and secured the rotor portion in a vice. Make sure to protect the rotor by using rubber blocks or wood between the vice and the rotor. Then I took a 24mm socket and removed the pulley nut. The torque spec for that M16 x 1.5 nut is 25-32 ft/lbs. Good luck.
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Any sign of locktight perhaps requiring some heat to break?


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I've had good success with a nifty little belt-wrench that I picked up at Sears a few years back. It is basically a handle with a long rubber belt. You wrap the belt around whatever you want to hold or turn (I've used it on oil filters, alternator pulleys, etc.), feed the belt into a slot, and twist. I used it to hold the pulley and then used an impact wrench to get the nut off the alternator, as suggested. It is kind of like using the old alternator belt, but the handle of the belt-wrench allows for you to exert more force, gives more leverage. Just a thought.

p.s. The alternator pulleys on the Ferraris are specially designed, so try not to damage it or lose it. You can't just go out and pick up any old replacement at any parts store or alternator shop. When I had a problem with my 328 pulley, I was able to get a new one from Daniel at Ricambi America. Otherwise, they are hard to find.

 

I bought the 7M950 (superformance part 117435). On their website, it stated this was for a 308 GTSi. The 1000mm is listed as a QV, so I did not buy it. According to Gates' website, there is a local distributor near me. I will see if I can get one. Again, this was a spare to keep so no big deal. It will probably cost me more to return ship it. Anyone need a 7M950, good price?

P.S. Ricambi also lists the 308GTSi as the 117435.

 

old belt is 975mm

 

7M975 received and installed, works like a charm

 

Is that M16 x 1.5 nut is 25-32 ft/lbs. correct I have a $$$ rebuilt unit and need to put the pulley on my very knowledgeable good friend suggested an impact wrench to reinstall but I dont want to mess this up. It is off the car and does not have a allen shaft...