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alternator fan nut, counter clockwise removal
Posted by: Saxon ()
Date: June 23, 2020 02:19PM

Hi, I am new to the forum and am enjoying learning basic maintenance, repair and upkeep. At the same time, I am cracking open some school books and watching you tube videos about electricity, magnetism, or differential expansion of metals. If I could go back to school, I would train as a mechanical engineer.

I am assuming the alternator fan nut on my 1966 140 4-speed Coupe rotates counterclockwise to remove the external bladed fan so I can replace the bearing at the pulley end.

I believe counter clockwise because the fan blades are rotating clockwise and this would help keep the nut tight.


It is stamped on the outside with:

1100639 37A
5L29 12v NEG

There is a hex key slot at the center of the spindle and a 15/16 nut around that.

Thanks!

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Re: alternator fan nut, counter clockwise removal
Posted by: steve c goodman ()
Date: June 23, 2020 02:32PM

Welcome to CCF. You are correct CCW will loosen the nut. Impact gun will make it simple, either air or electric. Just hold pulley with rag inside your hand and pull trigger and it is off. No need to have fixture etc to hold anything.

You should make a sig line with your first name/city and make and model of your car. You never know but someone here may be close to you to help.

Also the local club scene can help and many times the members have parts too.. Look at www.corvair.org which is CORSA (national club) for info about a club in your area Join CORSA too, they help with events and the magazine (COMMUNIQUE) is worth reading each month.

best wishes, Steve
Rear Engine Spec. Inc. Golden, Colo.

1962 spyder 3.0L turbo---1965 Crown V8
1967 monza 110/4---1968 monza 110/4
1971 amante gt 110/4
CORSA/RMC/PPCC/V8 Registry

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Re: alternator fan nut, counter clockwise removal
Posted by: Lane66m ()
Date: June 23, 2020 02:50PM

Remember to torque it back to 50 ft-lbs. GM AC Delco Spec. There is a photo I posted in the "show us your tools" discussion showing how to set up for the torque procedure. But there are other ways to do it also.

Al Lane
Ellabell, GA 31308

1966 Monza Coupe, 110 hp, 4 Spd
1966 Monza More Door 110 hp, PG
1968 Camaro SS Coupe 350 CI 295+ hp PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
1947 Farmall A tractor 15 hp


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Re: alternator fan nut, counter clockwise removal
Posted by: 48kb1panel ()
Date: June 23, 2020 05:46PM

Al, can you send a link to your post I can't find it.thanks. mike

My name is Mike Worrell living in southern Iowa my vairs are a 64 2dr convertible monza 900 with 110 motor 4 speed light yellow with blk interior. Then a few months ago I got a 65 2 Dr convertible monza 900 with 110 motor 4 speed
Also light yellow with blk interior. Not sure what gear ratio as of now I'll have a look and up date. I really like them both but really liking the 65. They really made a lot of changes in a 1 year difference ????

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Re: alternator fan nut, counter clockwise removal
Posted by: MattNall ()
Date: June 23, 2020 05:52PM

Mike!!! you need to practice "SEARCH" ,here Fast and easy! MINIMUM 4 Characters! an search ALL DATES!!

[corvaircenter.com]

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: alternator fan nut, counter clockwise removal
Posted by: 48kb1panel ()
Date: June 23, 2020 06:22PM

Right you are Matt. Thank you for the helpsmileys with beer

My name is Mike Worrell living in southern Iowa my vairs are a 64 2dr convertible monza 900 with 110 motor 4 speed light yellow with blk interior. Then a few months ago I got a 65 2 Dr convertible monza 900 with 110 motor 4 speed
Also light yellow with blk interior. Not sure what gear ratio as of now I'll have a look and up date. I really like them both but really liking the 65. They really made a lot of changes in a 1 year difference ????

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Re: alternator fan nut, counter clockwise removal
Posted by: Lane66m ()
Date: June 24, 2020 01:46AM

Make sure your torque wrench is rated to torque in a ccw irection.

If not, you will have to use a crowsfoot on the nut with a torque wrench. Holding with a allen wrench socket and ratchet. You will have to make a calculation to applied torque vauue since torque wrench won't be directly over the center of the nut. Torque value will be a bit lower.

Al Lane
Ellabell, GA 31308

1966 Monza Coupe, 110 hp, 4 Spd
1966 Monza More Door 110 hp, PG
1968 Camaro SS Coupe 350 CI 295+ hp PG
1964 Greenbrier Deluxe, 6 dr, 80 hp car engine, PG
1947 Farmall A tractor 15 hp


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Re: alternator fan nut, counter clockwise removal
Posted by: 66vairman ()
Date: June 24, 2020 09:15AM

Saxon Wrote:
-------------------------------------------------------
> Hi, I am new to the forum and am enjoying learning basic maintenance, repair and upkeep. At the same time, I am cracking open some school books and watching you tube videos about electricity, magnetism, or differential expansion of metals. If I could go back to school, I would train as a mechanical engineer.
>
> I am assuming the alternator fan nut on my 1966 140 4-speed Coupe rotates counterclockwise to remove the external bladed fan so I can replace the bearing at the pulley end.
>
> I believe counter clockwise because the fan blades are rotating clockwise and this would help keep the nut tight.
>
>
> It is stamped on the outside with:
>
> 1100639 37A
> 5L29 12v NEG
>
> There is a hex key slot at the center of the spindle and a 15/16 nut around that.
>
> Thanks!

The Corvair alternator rotates reverse compared to other GM vehicles of the time so it has a UNIQUE fan. I would make sure you have the correct fan. The alternator nut threads are the same as other GM cars (CCW to loosen). Yes the Corvair alternator reverse rotation means the nut does NOT self tighten. It is important to torque the nut properly. I've only seen one nut come loose, but it certainly ruined the alternator.

As Steve mentioned - Am impact gun works well to loosen or tighten the nut. I use thick welding gloves to hold the fan. If you try to jamb the fan with a hard tool the impact gun action will bend the fan against a hard tool.

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Re: alternator fan nut, counter clockwise removal
Posted by: Saxon ()
Date: June 27, 2020 11:48AM

Thanks for all input and advice. Job complete, smooth rotation and loud scraping noise gone. The battery was 12.9 volts after a test drive. Best part is that I am learning about mechanics and the car.

I am fortunate to have 2 nearby chapters and a nearby "Yoda" named Seth. But he has a day job, too. After some reading & sage advice, I tackle and learn as much as I can. This time was also a good opportunity to introduce myself and reach out to the forum.

SOME REMINISCENCES into my first alternator dive:

$13.99 National bearing (203F O'reily) was made in China but better than the broken one. $7.99 smaller National bearing (MNJ-471-S O'reily) was actually a US made Federal Mogul.

Old large bearing came out easy. New one almost "fell in" after a hour in the freezer and alternator housing in sun.

Old small end bearing required more forceful tapping. New one was given some tapping with a 2 lb hammer despite the same treatment above.

The sage advice of a paperclip was helpful to keep the brushes down when inserting rotor on back casing. Bending the right radius and length of large paper clip was important because the inner brush was stubborn. The "click" of brush engagement upon installing rear housing was nice to hear.

I goofed on reassembly of the front housing. My pictures helped return it to the proper alignment and it only required the removal of the thinner, long four bolts without having to remove pulley wheel nut. Next time, I will mark front and back housing before disassembly.

My first purchase of an air compressor and air gun. Bought a craftsman single pancake 150 psi and 90 psi 400 ft lbs wrench. Am still giddy at all the things I can do now.

I rubbed some silicone grease in the belt and used 45 degree twist technique between my finger & thumb to set the belt cold.

SOME QUESTIONS:

Does the air tool and accessory threading require teflon tape. I tried with and without and did not notice a difference for this job. I am not using now because I think bits of the tape may get sucked into the tools.

Where are the magnets on the rotor. The semi occluding jaws of metal were not magnetic. Are they inside the winded copper or does electrical flow amplify the magnetism.

I was surprised how large & beefy the pulley end bearing was - size of an Eisenhower coin dollar. It was dry & missing one pea size ball bearing that had disintegrated. Why such a large bearing? My conjecture:
either large loads are placed on this and/or this casing is used across larger vehicles.

SF Bay Area
Marina Blue '66 Coupe 4-spd 140 3.27 axle 14" minilites
Adopted May 2020

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Re: alternator fan nut, counter clockwise removal
Posted by: MattNall ()
Date: June 27, 2020 04:11PM

Same bearing used in higher amp model with 70 ft. lb. tension on the belt!

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

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Re: alternator fan nut, counter clockwise removal
Posted by: Frank DuVal ()
Date: June 27, 2020 08:38PM

Quote
Saxon
1. Does the air tool and accessory threading require teflon tape. I tried with and without and did not notice a difference for this job. I am not using now because I think bits of the tape may get sucked into the tools.

2. Where are the magnets on the rotor. The semi occluding jaws of metal were not magnetic. Are they inside the winded copper or does electrical flow amplify the magnetism.

3. I was surprised how large & beefy the pulley end bearing was - size of an Eisenhower coin dollar. It was dry & missing one pea size ball bearing that had disintegrated. Why such a large bearing? My conjecture:
either large loads are placed on this and/or this casing is used across larger vehicles.

1. I use PTFE (Teflon ­®Dupont) tape on air hose connections. I make sure to leave the first thread (the one that goes into the female part first) clear of tape. I also have used pipe dope with great success.

2. The alternator does not store magnetism like a generator does. This is why generators need "polarizing" and alternators do not. The field (that rotating part you reference) is connected to voltage through the voltage regulator, and this makes the magnetic field variable.

3. Delco uses a standard 6203 bearing in most every application of generator and alternator! Shields change, depending on if there are oil cups or not. I guess it is one of those "why change what works for over 70 years" type of thing.winking smiley

Frank DuVal

Fredericksburg, VA

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Re: alternator fan nut, counter clockwise removal
Posted by: Timothy Shortle ()
Date: June 27, 2020 08:51PM

Congrats! Sounds like you have a nice car there. You are near a "Seth"? We have famous Seth E. in our midst
who only has been around Corvairs over 50 years. Except ours no longer has a day job but has his own business
and is semi retired. As for your questions you can put teflon tape on your air hose and fittings but it is hardly
needed. I just put a little bit of oil on mine and tighten them up. Why such a big alternator bearing? This is what the engineers decided was needed. It also may have been cheaper to use it as it was in many many other applications.
Magnets on the rotor? I don't think it has any and the same with the armature.

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Re: alternator fan nut, counter clockwise removal
Posted by: joelsplace ()
Date: June 27, 2020 09:20PM

The bearing isn't really oversized. The cheap ones fail regularly. The good ones fail also eventually. I agree that it is probably likely that GM just used whatever was cheapest that they thought would work. The little one in the back almost never fails and when it does it is usually because the grease is gone.
I've never been able to get air hoses to seal without sealer done like Frank described.

Joel
Northlake, TX
5 Ultravans, 114 Corvairs and counting...

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