Bolt Size For Replacement Fan Clutch
 

I picked up a fan clutch from advanced today, using the 2000 express v6 no a/c. Of course, it didn't come with bolts. So I went and got (4) 3/8 coarse thread bolts. Feels like they fit loose in 2 holes, tight in the other 2.

Am I using the right size? Anyone know what size it takes?

Oh man I dont know, the one I got from AutoZone came with bolts and lock washers.

Seems I recall a post that the holes in the fan have to be reamed slightly to line up properly with the GM clutch

luckgreg

Yup, I had to open the holes up with a 10mm drill bit. Bolt size is m10 x 1.5 pitch(metric). I couldn't get bolts short enough, so i had to put a regular washer and a lock washer on each bolt to keep them from bottoming out.

But all went well. Works great. And i didn't realize how much my fan was not turning until I got the new clutch on.

No idea what fan clutch you used, but the Imperial 215158 & 215157 use 3/8"-16x 5/8" or so.

It is a 215157. I took it right in valu hardware with me, the 3/8 would kinda go in, the 10mm fit alot better.

Weird...I just installed one about a month ago and 3/8" is what it definitely took. Maybe they've done two different production runs.

Or it might have been the one I had. It looked like either someone tried installing it or someone did a really crappy job cleaning the threads after taping the holes. I had to clean out a bunch of shavings from the holes when I first got it. I just chalked it up to a cheap part, but maybe that was it.

Ah, yeah, that makes sense. I've installed 2 of them and on both the bolt holes were clean. Of everyone who's installed one, you're the first I've heard to use metric bolts.

I'd consider taking it back and getting another. If the threads are messed up they will eventually let go, even if the metric bolts are tight now.
I'd take a 3/8"-16 with you to make sure the new one is ok.