'67 L79 alternator fan and pulley, C60, N40

[Leif A.]

I am attempting to replace the incorrect one piece alternator fan & pulley with the correct two piece for the above referenced car. Before I go all gorilla on this thing, a little advice is needed. I have removed the pulley/fan retaining nut and washer (the picture is a "before" pic). The problem is the one piece unit won't slide off the shaft. It almost feels like it is press fitted on. I obviously don't want to do anything radical here...what am I missing from this simple task.

[Leif A.]

Re: '67 L79 alternator fan and pulley, C60, N40

Any ideas??

[Joe L.]

Re: '67 L79 alternator fan and pulley, C60, N40

Any ideas??

Leif------


These pulleys are not an interference fit on the shaft. However, they often "stick" and can be difficult to remove. A small puller may be your best bet.

[Leif A.]

Re: '67 L79 alternator fan and pulley, C60, N40

Leif------


These pulleys are not an interference fit on the shaft. However, they often "stick" and can be difficult to remove. A small puller may be your best bet.

Thanks, Joe...I'll put some muscle to it.

[Joe L.]

Re: '67 L79 alternator fan and pulley, C60, N40

Thanks, Joe...I'll put some muscle to it.

Leif------


By the way, I'm not so sure that one piece pulley/fan might not be original for your application. Does your car have a deep groove pulley set or a standard groove pulley set? Also, what is the OD of the pulley of your one piece pulley/fan?

[Leif A.]

Re: '67 L79 alternator fan and pulley, C60, N40

Joe,

The TIM&JG, 5th edition for '67 states on page 150 that base engines use a one piece alternator fan-pulley and that alternators on the optional engines use a separate pulley and fan combination. I still haven't been able to remove the one piece unit that is currently on the alternator so it's a bit tough to get an accurate measure of the pulley but it appears to be about 2 3/4" vs the 3 1/4" separate pulley. Attached picture is of the groove on the attached pulley...hope you can tell if it's deep groove or not.

By using the separate pulley and fan it appears this will push the belt forward about 1/8" which would allow a bit more clearance for the alternator belt as it passes by the power steering pump. Currently, the belt is barely clearing the front of the PS pump.

Please look at this post #23 and share your opinions.

https://www.forums.ncrs.org/showthread.php?112450-Correct-1965-327-350-W-AC-amp-PS-Pulley-Configuration-(includes-pictures)&highlight=pulleys

[Joe L.]

Re: '67 L79 alternator fan and pulley, C60, N40

Joe,

The TIM&JG, 5th edition for '67 states on page 150 that base engines use a one piece alternator fan-pulley and that alternators on the optional engines use a separate pulley and fan combination. I still haven't been able to remove the one piece unit that is currently on the alternator so it's a bit tough to get an accurate measure of the pulley but it appears to be about 2 3/4" vs the 3 1/4" separate pulley. Attached picture is of the groove on the attached pulley...hope you can tell if it's deep groove or not.

By using the separate pulley and fan it appears this will push the belt forward about 1/8" which would allow a bit more clearance for the alternator belt as it passes by the power steering pump. Currently, the belt is barely clearing the front of the PS pump.

Please look at this post #23 and share your opinions.

https://www.forums.ncrs.org/showthre...hlight=pulleys

Leif-------


It's not whether the alternator pulley is deep groove, or not, but rather whether the pulley SET on your car is deep groove, or not. All of the 1967-era one piece pulley/fan combinations were standard groove. In any event, the easiest way to tell if the pulley SET is standard or deep groove is by whether the power steering pump pulley is cast iron or stamped steel.

It should not be that difficult to measure the OD of the alternator pulley with the pulley mounted to the alternator. Do you have a vernier caliper? If not, you should be able to "eyeball" it with a tape measure. It's not important that it be accurate to a "gnat's ass".

[Leif A.]

Re: '67 L79 alternator fan and pulley, C60, N40

Leif-------


It's not whether the alternator pulley is deep groove, or not, but rather whether the pulley SET on your car is deep groove, or not. All of the 1967-era one piece pulley/fan combinations were standard groove. In any event, the easiest way to tell if the pulley SET is standard or deep groove is by whether the power steering pump pulley is cast iron or stamped steel.

It should not be that difficult to measure the OD of the alternator pulley with the pulley mounted to the alternator. Do you have a vernier caliper? If not, you should be able to "eyeball" it with a tape measure. It's not important that it be accurate to a "gnat's ass".

Joe,
The power steering pulley is stamped steel and, as I stated earlier, the alternator pulley appears to be about 2 3/4"...definitely smaller than 3"

[Joe L.]

Re: '67 L79 alternator fan and pulley, C60, N40

Joe,
The power steering pulley is stamped steel and, as I stated earlier, the alternator pulley appears to be about 2 3/4"...definitely smaller than 3"

Leif-------


If you have a stamped steel power steering pump pulley, then you have a standard groove pulley set. This is as it should be for your application.

The pulley/fan you have is almost certainly a GM #3909817 with a pulley that is 2-21/32" OD. That pulley/fan is very likely original for your application. This is a somewhat rare pulley first used for 1967 and had limited application. It's hard to believe that it would have found its way "accidentally" on your car.

You may find the number 3909817 stamped on the fan or on the pulley. These pulleys were usually originally finished in black phosphate. Yours looks like it might have been painted at some point. The paint appears rather thick.

[Leif A.]

Re: '67 L79 alternator fan and pulley, C60, N40

Leif-------


If you have a stamped steel power steering pump pulley, then you have a standard groove pulley set. This is as it should be for your application.

The pulley/fan you have is almost certainly a GM #3909817 with a pulley that is 2-21/32" OD. That pulley/fan is very likely original for your application. This is a somewhat rare pulley first used for 1967 and had limited application. It's hard to believe that it would have found its way "accidentally" on your car.

You may find the number 3909817 stamped on the fan or on the pulley. These pulleys were usually originally finished in black phosphate. Yours looks like it might have been painted at some point. The paint appears rather thick.

Joe,
As always, very informative and interesting news. My '67 is a June 14 build. I had always thought that the correct application for my car was the two piece setup and the TIM&JG affirmed that. But your insight has changed my mind. I'm going to leave it "as is" and return the two piece pulley and fan. Thanks, again, for the educational info. BTW, many items on my car were powder coated instead of painted during the restoration (this pulley is one of many items)...NTP, I know, but an attempt to protect better than factory.

[Leif A.]

Re: '67 L79 alternator fan and pulley, C60, N40

I'm resurrecting this 11 month old thread for some edification. I'm looking for other owners of late '67s with L79, M21, C60 and N40 and no K19. Joe Lucia convinced me that my setup (pictured in the first post) was possibly original and was a late introduction piece. There is no part number on the facia and I wasn't able to easily remove the pulley/fan combo to observe the reverse side. I was hoping for owners with similar equipment to post a picture of their alternator pulley/fan. If needed, the other options on my car are in my signature. Thanks in advance.

[Leif A.]

Re: '67 L79 alternator fan and pulley, C60, N40

TTT, hoping for some new looks.

[William F.]

Re: '67 L79 alternator fan and pulley, C60, N40

A little different slant on this thread.
My '67 L79 has factory C60. If I want to add factory type PS, what would I need in way of pulleys, belts, etc.? Different alternator bracket or spacer? Do any of the vendors off a complete kit that would be as close as possible to factory original ?
Thanks

[Neal K.]

Re: '67 L79 alternator fan and pulley, C60, N40

I'm resurrecting this 11 month old thread for some edification. I'm looking for other owners of late '67s with L79, M21, C60 and N40 and no K19. Joe Lucia convinced me that my setup (pictured in the first post) was possibly original and was a late introduction piece. There is no part number on the facia and I wasn't able to easily remove the pulley/fan combo to observe the reverse side. I was hoping for owners with similar equipment to post a picture of their alternator pulley/fan. If needed, the other options on my car are in my signature. Thanks in advance.

Hi Leif,
Merry Christmas or Happy Holiday whichever is appropriate.
My early production, #00179, 67 L79 with C60 and P/S has a 2 piece alternator pulley, 2 Piece crankshaft pulley and stamped steel power steering pump pulley. Not sure if this information helps or not.
Best regards
Neal

[Joe L.]

Re: '67 L79 alternator fan and pulley, C60, N40

Hi Leif,
Merry Christmas or Happy Holiday whichever is appropriate.
My early production, #00179, 67 L79 with C60 and P/S has a 2 piece alternator pulley, 2 Piece crankshaft pulley and stamped steel power steering pump pulley. Not sure if this information helps or not.
Best regards
Neal

Neal------


For the most part, you have what you should have for your application. I'm not so sure about the alternator pulley, though.

I think that part of the problem with this pulley situation may involve the fact that the factory may have used different pulley configurations for the same applications. I think there was considerable confusion about this and this especially applied to alternator pulleys.