How to tell if it's any good? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Steve Cole · 09-09-2013, 02:23 PM

Thinking of hitting up some junkyards this week looking for a 18" fan & fan clutch. Do these clutches go bad? if so, how do you tell? Will any Chevy 18" fan clutch setup work, like on later year model yehicles?

Also, no matter what tools you bring, you never seem to have everything you need. What tools do I need to bring?

Thanks,

Tx Firefighter · 09-09-2013, 02:25 PM

You need a 1/2 inch wrench to remove the fan clutch from the water pump. The fan will remain bolted to the clutch and you remove it as an assembly.
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NC_John · 09-09-2013, 06:49 PM

Quote:

Originally Posted by Steve Cole

Thinking of hitting up some junkyards this week looking for a 18" fan & fan clutch. Do these clutches go bad? if so, how do you tell? Will any Chevy 18" fan clutch setup work, like on later year model yehicles?

Also, no matter what tools you bring, you never seem to have everything you need. What tools do I need to bring?

Thanks,

you're not putting an electric fan on that hotrod of yours?

swamp rat · 09-09-2013, 06:50 PM

My understanding (don't have one myself on my project) is that they turn semi firmly smoothly and don't wobble then they still good, but there could be something to the internals I don't know about checking. its designed to slip on acceleration then re engage when the engine rpm stabilizes.

If the fan shroud is on you will need a 3/3" socket, the 1/2 has been mentioned, i would use a small extension to keep your knuckles clear of the fan blade. I heavy pare of cutters or a knife to cut the fan belt will make it easy, ir the tools to remove the alternator, add a 9/16 and 1/2" wrench and socket to the box for that.

Tx Firefighter · 09-09-2013, 07:39 PM

You can't use any extensions on this job. All you can do is use a wrench. You have side access to the four nuts that hold the clutch on. No straight on access so no socket option. Leave the belts in place and tight to allow you to break the four nuts loose easier. Once you remove the four nuts, just tip the fan and clutch out of the shroud and lift it up. You'll likely have to push the upper radiator hose out of your way with one hand while you lift the fan out with the other.
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slow-1 · 09-09-2013, 09:14 PM

When I worked as a parts puller in a junk yard in the mid 80's I carried 3 combo wrenches (1/4 up to 9/16, total of 6 sizes) and a small channel lock in my back pocket...I could get almost any small part with those...and a lot of big parts.

Go to a parts store and ask to see a fan clutch...take it out of the box and turn the two ends opposite directions to each other, then you know how a good one feels...it is kind of hard to express in words.

**WIDESIDE72** · 09-09-2013, 10:47 PM

You shouldnt see a lot of oil on the clutch. That means its leaking and bad or soon bad. It should turn with some resistance and not wobble. Make sure the fan blades are straight, no dents or bends. I usually check for a bad one on running vehicles by placing a couple pieces of masking tape from the blades to the shroud and taking the truck for a drive, getting up to oeprating temp. Shut the engine off and check to see if the tape is broken loose. The fan clutch should have locked up and pulled loose if its good.
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Andy4639 · 09-09-2013, 11:15 PM

When checking the bone yard for a clutch remember to spin the fan blade and if it just spins free it's bad. U shouldn't get more than 1/2 to 3/4 of a full revolution if it's good.
I have to ask though why not go buy a new one and have the good warm fuzzy feeling!

Brand new at O-rielly's. $40.00

http://www.oreillyauto.com/site/c/de...3389&ppt=C0331

**WIDESIDE72** · 09-09-2013, 11:28 PM

Quote:

Originally Posted by Andy4639

When checking the bone yard for a clutch remember to spin the fan blade and if it just spins free it's bad. U shouldn't get more than 1/2 to 3/4 of a full revolution if it's good.
I have to ask though why not go buy a new one and have the good warm fuzzy feeling!

Brand new at O-rielly's. $40.00

http://www.oreillyauto.com/site/c/de...3389&ppt=C0331

While a new clutch is a good idea the O.P. stated he needs the clutch and fan. Why not give the used clutch a shot since hes pulling it all anyway?
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Andy4639 · 09-10-2013, 02:45 AM

Quote:

Originally Posted by WIDESIDE72

While a new clutch is a good idea the O.P. stated he needs the clutch and fan. Why not give the used clutch a shot since hes pulling it all anyway?
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The fan can be bought new also if u want it. Well at least last year it could. I got a new from the Chevy dealer.

Not saying not to but for the time spent in the yard going through all the fans u could have bought it and had installed.
I love yarding when I have time.

68shortfleet · 09-10-2013, 03:41 AM

Quote:

Originally Posted by Steve Cole

Will any Chevy 18" fan clutch setup work, like on later year model yehicles?

Thanks,

Don't forget that almost anything GM with a serpentine belt drive will spin in the wrong direction for our trucks since they went to the reverse rotation water pump. I think that this eliminates everything from 88 and up in the trucks and maybe even earlier. Not sure when the cars went to the reverse rotation serpentine system.

Steve Cole · 09-10-2013, 10:25 AM

Andy, I may end up buying a new one but for me it's more of the "thrill of the hunt". I love plundering around in junkyards looking for undiscovered treasures.

My ultimate find would be a set of buddy buckets but I'm not holding my breath.

Thanks for the tip 68shortfleet! I probably would not have thought about that.

NC_John, maybe oneday but for now, I just want it on the road.

09-09-2013, 02:23 PM	#1
Steve Cole Registered User Join Date: May 2012 Location: Faith,NC Posts: 1,626	How to tell if it's any good? Thinking of hitting up some junkyards this week looking for a 18" fan & fan clutch. Do these clutches go bad? if so, how do you tell? Will any Chevy 18" fan clutch setup work, like on later year model yehicles? Also, no matter what tools you bring, you never seem to have everything you need. What tools do I need to bring? Thanks, Last edited by Steve Cole; 09-09-2013 at 02:26 PM. Reason: Forgot something.

09-09-2013, 02:25 PM	#2
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: How to tell if it's any good? You need a 1/2 inch wrench to remove the fan clutch from the water pump. The fan will remain bolted to the clutch and you remove it as an assembly. Posted via Mobile Device

09-09-2013, 06:50 PM	#4
swamp rat Registered User Join Date: Oct 2007 Location: Spanaway Posts: 8,451	Re: How to tell if it's any good? My understanding (don't have one myself on my project) is that they turn semi firmly smoothly and don't wobble then they still good, but there could be something to the internals I don't know about checking. its designed to slip on acceleration then re engage when the engine rpm stabilizes. If the fan shroud is on you will need a 3/3" socket, the 1/2 has been mentioned, i would use a small extension to keep your knuckles clear of the fan blade. I heavy pare of cutters or a knife to cut the fan belt will make it easy, ir the tools to remove the alternator, add a 9/16 and 1/2" wrench and socket to the box for that. __________________ Mike. Swamp Rat build thread : http://67-72chevytrucks.com/vboard/s...d.php?t=595019 72 3/4T 4X4 4" BDS Lift 33" BFG's

09-09-2013, 07:39 PM	#5
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: How to tell if it's any good? You can't use any extensions on this job. All you can do is use a wrench. You have side access to the four nuts that hold the clutch on. No straight on access so no socket option. Leave the belts in place and tight to allow you to break the four nuts loose easier. Once you remove the four nuts, just tip the fan and clutch out of the shroud and lift it up. You'll likely have to push the upper radiator hose out of your way with one hand while you lift the fan out with the other. Posted via Mobile Device

09-09-2013, 09:14 PM	#6
slow-1 Registered User Join Date: May 2013 Location: Central NC Posts: 830	Re: How to tell if it's any good? When I worked as a parts puller in a junk yard in the mid 80's I carried 3 combo wrenches (1/4 up to 9/16, total of 6 sizes) and a small channel lock in my back pocket...I could get almost any small part with those...and a lot of big parts. Go to a parts store and ask to see a fan clutch...take it out of the box and turn the two ends opposite directions to each other, then you know how a good one feels...it is kind of hard to express in words. __________________ 1972 Cheyene C-10 "Ole Green" My Grandfathers truck (early 70's to 1983) My first vehicle (1983) Original 350 (3 rebuilds) 700R4 from Bowtie Overdrives

09-09-2013, 10:47 PM	#7
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,494	Re: How to tell if it's any good? You shouldnt see a lot of oil on the clutch. That means its leaking and bad or soon bad. It should turn with some resistance and not wobble. Make sure the fan blades are straight, no dents or bends. I usually check for a bad one on running vehicles by placing a couple pieces of masking tape from the blades to the shroud and taking the truck for a drive, getting up to oeprating temp. Shut the engine off and check to see if the tape is broken loose. The fan clutch should have locked up and pulled loose if its good. Posted via Mobile Device

09-09-2013, 11:15 PM	#8
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,936	Re: How to tell if it's any good? When checking the bone yard for a clutch remember to spin the fan blade and if it just spins free it's bad. U shouldn't get more than 1/2 to 3/4 of a full revolution if it's good. I have to ask though why not go buy a new one and have the good warm fuzzy feeling! Brand new at O-rielly's. $40.00 http://www.oreillyauto.com/site/c/de...3389&ppt=C0331 __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

09-10-2013, 10:25 AM	#12
Steve Cole Registered User Join Date: May 2012 Location: Faith,NC Posts: 1,626	Re: How to tell if it's any good? Andy, I may end up buying a new one but for me it's more of the "thrill of the hunt". I love plundering around in junkyards looking for undiscovered treasures. My ultimate find would be a set of buddy buckets but I'm not holding my breath. Thanks for the tip 68shortfleet! I probably would not have thought about that. NC_John, maybe oneday but for now, I just want it on the road.



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