I've read everything related to alternator pulley size from my search. The only thing I know is that it's supposed to be 62 mm but have no idea where that measurement is taken.

Can anyone with the correct pulley slap a tape measure across it and give me a measurement from the edge of the flange to the opposite edge.....so I don't have to remove the belt just to check.

Thanks guys.
Smitty

2.5" pitch diameter

Pulleys are usually measured at their pitch diameter.

After a smaller pulley?

no, just trying to make sure I got the right one on my AZ reman. And if it's supposed to be 2 1/2 inches diameter where the belt rides then mine is too small - it measures 2 7/16ths across the flange.

I always switch the pulleys from the old to the new so I know I have the right one.

My alternator has the wrong size pulley. Where can I get the right one?

ok, let me rephrase the question. The diameter of the pulley on my truck(including the lip/flange/whatever its called) is 2 7/16ths inch. Is that the small gasser pulley?

I plan on returning my alternator if it is the wrong pulley - it has a lifetime warranty.....so I need to know this info before I go there tomorrow.....like, what is the correct measurement?...as in I need to walk in there with a tape measure and say "see, this is the wrong size" My dial caliper is at work and I'm off for three weeks(I know AZ doesn't have one).

man, this is more difficult than I anticipated...:(

The OD of the pulley for the outside lip/flange is 2 and 5/8 inches. The top of the grooves the belt acually rides on is 62mm or 2 and 7/16 inches. This is for the 92/93 mechanical engines, the newer engines changed thier belt drive systems a couple of times and maybe different than this. I'm certain of these figures since my alt. is still original with 190,000 miles (knock on wood). The typical small block chevy alt is 2 and 7/16 inches for the outside lip/flange OD. and is 2 and 1/4 inches (57mm) to the top of the grooves the belt rides on

Assuming a correct engine speed of 2200rpm the SB chevy alt. pulley would show 2400rpm and at correct engine speed of 3600rpm and the SB chevy alt pulley would show 3925 rpm.

OK, went back to AZ told em of my dilemma. They pulled up all the stuff I've purchased from them over the years(I was surprised how much there was) and they couldn't find the alternator I purchased less than six months ago. He looked up the part number and pulled one from the shelf - same thing, 57 mm pulley. So, he said hang on let me get a new one off the shelf, not a reman. So, he comes back with a brand new, Duralast Gold HD alternator for a 92 6.5 TD(I watch while he was looking it up to make sure he brought back the correct one). Same thing - 57 mm pulley. He says "tell you what, this pulley looks bigger (even though I had him measure it and it was clearly 2 7/16 across the lip) - how bout I just give you this one" I said 'well, I'll go home and pull my other one off and bring it back tomorrow' he said "no, just keep it, and take this one with you".

So, now I have two working alternators with the incorrect pulley size...so, anyone know where I can purchase the correct pulley?

Thanks
Smitty

What the hell, I can't ever get something for free like that........Sorry for your delima but shit you got a free alternator. Go to a wrecking yard and see if you can find a trashed 92-93 6.5 and rob the alternator pulley.

I'm in the same boat. been to three auto parts and all have the 57mm pulley. same on my truck. I guess it's either the junk yard or the stealership.

To me that sounds like you have a parts guy who doesn't know what he is talking about, and tride to bribe you with free parts ti get you out of his hair. Problems like the one you are haveing are why I am leary about buying aftermarket company parts for my truck.

Find out where they send their cores and call them. They'll probably be able to fix you up.

What the hell, I can't ever get something for free like that........Sorry for your delima but shit you got a free alternator. Go to a wrecking yard and see if you can find a trashed 92-93 6.5 and rob the alternator pulley.

Yeah, I never have that kinda luck either...and the funny thing was I was in and out of there in less than ten minutes. It wasn't like I was pissed or anything - I was totally cool and was just checkin to see if I could in fact get one with the correct pulley..... when he gave it to me he said (as he leaned toward me and spoke in a lower tone) "listen dude, I totally trust you, I believe you bought it here and apparently it's the wrong one so just take this one and try it" I think I was dumbfounded that he was giving me a brand new alternator - so I just kinda looked at him and said "uh,...ok...thanks"

Off to the u-pull-it yard next week.