Alternator Pulley

[Erv M.]

On a 69 alternator, in replacing a pulley are the threads standard, meaning to loosen is counterclockwise or are thet reversed?

[Wayne M.]

Re: Alternator Pulley

On a 69 alternator, in replacing a pulley are the threads standard, meaning to loosen is counterclockwise or are thet reversed?

Erv -- I'm pretty sure they're standard; ie facing bolt and front of alternator, turn NUT clockwise to tighten.

But when you insert the 5/16" hex wrench in the end of the rotor shaft, if you chose to hold the wrench on the nut stationary, then you turn the hex in the shaft end counter-clockwise to tighten.

[Joe L.]

Re: Alternator Pulley

Erv -- I'm pretty sure they're standard; ie facing bolt and front of alternator, turn NUT clockwise to tighten.

But when you insert the 5/16" hex wrench in the end of the rotor shaft, if you chose to hold the wrench on the nut stationary, then you turn the hex in the shaft end counter-clockwise to tighten.

Wayne and Irv-----


Yes, that's how it is, for sure. Also, the original nut, GM #1915172, was a standard, right-hand thread, 5/8-20 nut, but thinner (1/4") than a standard hex nut. The later GM replacement, GM #1911324, was a bit thicker, but still thinner than a standard hex nut.

GM also listed another nut for Corvettes. It was GM #3947122. This nut was 5/8-20 X 1-3/8". This nut was NEVER used on a Corvette, though. I don't know what gave GM the idea it was.

[Scott S.]

Re: Alternator Pulley

Wayne and Irv-----


Yes, that's how it is, for sure. Also, the original nut, GM #1915172, was a standard, right-hand thread, 5/8-20 nut, but thinner (1/4") than a standard hex nut. The later GM replacement, GM #1911324, was a bit thicker, but still thinner than a standard hex nut.

GM also listed another nut for Corvettes. It was GM #3947122. This nut was 5/8-20 X 1-3/8". This nut was NEVER used on a Corvette, though. I don't know what gave GM the idea it was.

Joe,

I found some conflicting info regarding the alternator pulley washers, between what the AIMs depict and what the P&As say. My alternator is rebuilt and restored, so no originality clues there.

Apparently the GM 1911324 Hex Nut you mentioned above was also used for 1963-1964 alternator pulleys (63 & 64 P&A, Gr. 2.280).

Then it's GM 1915172 Hex Nut for 1965 through at least 1969. My question is about the associated Washers.


1) Should all 1963-1966 Corvette alternators have a Hex Nut (GM 1911324 for 63-64, GM 1915172 for 65-67) + Lock Washer (split) (GM 1888439) + Wave Washer (GM 1941978) securing the alternator pulley, in that order?

2) Should 1967 Corvette alternators have only the Hex Nut + Wave Washer securing the alternator pulley, or should 1967 have the split-lock washer too? The GM 1888439 split-Lock Washer was removed from Gr. 2.280 in the 67P&A, and my restored alternator appears to have a cad or zinc flat washer (approx. 1-3/32" OD) under the Hex Nut, with no split-lock washer. If there is a "wave" washer behind the flat washer, it must have a smaller OD, because I cannot see it.


Edit: Just noticed in the back of the 67P&A it says "1888439 USE 1941978 . . . . 8-66". If that is not an error, it seems to say to substitute a second GM 1941978 Wave Washer in place of the GM 1888439 split-lock washer?