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View Full Version : Has anyone adjusted the GM '97 fan clutch?



Heliraf
06-23-2020, 00:07
I towed my VW Vanagon on a car hauler trailer from LA to Las Vegas a week ago, about 5200 lbs total, and before the trip I did the cooling fan upgrade - put in a '97 fan clutch and the Duramax 9 blade fan. I was looking forward to hearing the fan howl and the temps drop like I've read about. Nope, didn't happen. The Burb didn't run way too hot, but on one or two of the climbs it almost got to 220 on the coolant temp. So started to read up about the GM fan clutches, and wished that I read up about them before. Turns out that GM raised the temp that they kick in at, due to customer complaints about the noise, duh.... Anyhow, so now I have a brand new fan clutch, that kicks in at way high temps, I presume, and am wondering if anyone has "clocked" them, and how easy or hard this is? Right now I can't picture what the coil assembly there looks like as I didn't pay particular attention when I was installing it, but I know some fan clutches are quite easy to adjust. I'll take a look at it when I get back to LA. Anyone have any experience or advice on this? I'm hoping I can adjust this new GM one and not have to put it in storage and get an expensive Kennedy one....

More Power
06-23-2020, 09:44
GM altered the engage temp for the Duramax fan-clutch back quite some years ago for what we think was to reduce noise (sacrifice cooling efficiency because of noise complaints), but I'm not aware of GM doing that for the 6.5.

You'd need to fabricate an adjustable thermostat coil because odds are against guessing and getting it right. I've seen adjustable ones for other applications, but as far as I know there isn't one for the 6.5.

a5150nut
06-23-2020, 16:57
Go talk to John Kennedy hes a vendor here. If i can be done he would know, if not he sells one he had built to engage at a lower temp.