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Can anyone tell me what the pulley width is on their alternator that goes with a '72 455? The alternator I bought, as well as the new alt belt ...the alt pulley is too narrow. The belt is roughing up it's edges and it sits too high in the channel of the pulley - as opposed to sitting in nice and flush on the water pump/crank pulleys.
Did you take the pulley off the alternator you turned in for a core? If so, go to the auto parts store where you bought it and see if they have your core sitting in the back, waiting to go to the warehouse.
Did you take the pulley off the alternator you turned in for a core? If not, go to the auto parts store where you bought it and see if they have your core sitting in the back, waiting to go to the warehouse.
Why are you still reading, do it NOW!
Hah, ( I know ). They're looking - but it's doubtful. It was about a month and a half ago...
Bummer. If they can't find your alternator core I'm sure someone knows the answer or can get you the part you need. Might have to go "downtown" to their warehouse location. Good luck.👍
Your car uses pulley P/N 1939845, which is 2.25" in diameter. It was used on just about all 1970-72 Olds full size cars with A/C. The new replacement pulleys that allegedly replace it do not look like the original. This photo is the alleged replacement.
The original looks like this.
Last edited by joe_padavano; Jul 23, 2023 at 09:15 AM.
Your car uses pulley P/N 1939845, which is 2.25" in diameter. It was used on just about all 1970-72 Olds full size cars with A/C. The new replacement pulleys that allegedly replace it do not look like the original. This photo is the alleged replacement.
Just re-reading the message, Joe, and while I appreciate the diameter and P/N, I do want to know the WIDTH of the pulley. Does anyone know that - across the "valley" of where the belt rides?
What size is the water pump and crank pulley? Alt pulleys usually are 3/8 inch 10mm-or 7/16in 11mm or 1/2in-13mm. What is your belt width. It should be marked on the belt and the package. Get a pulley to match the belt width. Let us know what you have
What size is the water pump and crank pulley? Alt pulleys usually are 3/8 inch 10mm-or 7/16in 11mm or 1/2in-13mm. What is your belt width. It should be marked on the belt and the package. Get a pulley to match the belt width. Let us know what you have
Well, leave it to me to NOT be able to easily answer the question. From what I can see, the crank pulley width for the alternator/power steering --- each ---- is approximately ...5/8 total width or 1 1/4 for both, which is much wider than what you said, unless you meant ONLY the width of the "belt channel" that the belt rides in. If that's the case, then from my eyes, it looks like they're 7/16" wide. On the "new" alternator, with the NEW pulley, the width of the belt channel is only 3/8" wide.
So if the belt fits wonderfully in the crank pulley, then I should get a 7/16" pulley for the alternator. Right?
That sounds right to me. You may want to find an original style shown above as it wont have the sharp edge against the belt that the replacement solid type have. I doubt if you will find one that is 2.25 inch diameter. Probably around 2 9/16 in dia.. It should work wellfor you.
Odd that all my local "auto parts" stores couldn't get/find a 7/16 pulley, but, one said "we have a box of a bunch from customers you're welcome to root through". So I did - BAMM, found one. FREE!!!!! Another problem solved. Thanks all.
