Author Topic: Fan Clutch  (Read 3454 times)

Offline shpark2

  • Newbie
  • Posts: 27
Fan Clutch
« on: October 03, 2007, 04:29:37 PM »
Can someone please share with me a way to check the fan clutch?

Offline Lt.Del

  • Andy aka:SgtDel
  • Senior Member
  • ****
  • Posts: 3864
  • DelbridgePhotography.com
    • www.delbridge.net
Fan Clutch
« Reply #1 on: October 03, 2007, 08:36:23 PM »
Quote
Can someone please share with me a way to check the fan clutch?

You trying to hijack this thread?  I know, you saw the word thermostadt.

If it is more than a few years old, chances are it needs replacing. The clutches are cheap and easy to replace.  Don't buy the whole fan assembly, don't need it.

People overlook these clutches when working on an a/c.  It supposed to pull cooler air thru the condensor and many times, they are bad and in need of replacement.  Dont assume that just because the truck doesnt overheat, the clutch is good. 

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 17821
Fan Clutch
« Reply #2 on: October 03, 2007, 09:29:39 PM »
The fan clutch can be checked by rocking it at 6 and 12 o'clock. If you see play and the waterpump shaft is tight the bearings are shot. As far as how the clutch works, when the fan sits overnight it will spin faster at first until the viscous fluid is thinned and the fan will slow down. When the coil heats up the fan will spin faster. It's purpose is to reduce engine drag.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

Offline shpark2

  • Newbie
  • Posts: 27
Re: Fan Clutch
« Reply #3 on: October 04, 2007, 09:42:00 AM »
Thanks Guys!  If the temp gauge was a fuel gauge, my truck always runs 3/4 full - sometimes straying into the last quarter where the little orange bit is near full.  I don't have my cold air intake tube connected to the radiator support from the air cleaner - I can't see how much that would help though.  Even today on the way to work, 35 degrees outside and still runs 3/4 hot.  Coolant is new, tstat is new, temp sender is new, water pump is unknown however.

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18127
    • http://www.73-87chevytrucks.com
Re: Fan Clutch
« Reply #4 on: October 04, 2007, 09:45:54 AM »
Does the guage ever move?

Offline shpark2

  • Newbie
  • Posts: 27
Re: Fan Clutch
« Reply #5 on: October 04, 2007, 09:50:09 AM »
Yeah it has full range movement, from dead cold to nearly full hot.  I replaced the sender because when I first got the truck, because it didn't move much at all.  The sender I got from parts store is not exactly same shape, I wonder if the resistance range is out a bit with the gauge.

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18127
    • http://www.73-87chevytrucks.com
Re: Fan Clutch
« Reply #6 on: October 04, 2007, 09:53:09 AM »
The sender would have to match that of the guage.  You can put a cheap mechanical temp gauge on there to check it.  Is the sender in the head?

Offline ccz145a

  • Senior Member
  • ****
  • Posts: 1393
Re: Fan Clutch
« Reply #7 on: October 04, 2007, 09:55:35 AM »
You might try this simple test: Start the engine when cold and let it heat up with the radiator cap off, when the water starts to flow go look at your guage and see where it is.

That will give you a baseline on what the guage reads at your thermostat temp and maybe an idea on if your sender is correct.

cp
1975 C10 Silverado LWB, 454CID, TH400, 10bolt 3.42
11MPG Downhill w/tailwind (but there ain't no hills here)

Offline shpark2

  • Newbie
  • Posts: 27
Re: Fan Clutch
« Reply #8 on: October 04, 2007, 09:57:27 AM »
No, it's just above #1+#3 plugs

Offline Captkaos

  • OWNER and Administrator
  • Administrator
  • Senior Member
  • *****
  • Posts: 18127
    • http://www.73-87chevytrucks.com
Re: Fan Clutch
« Reply #9 on: October 04, 2007, 10:59:47 AM »
No, it's just above #1+#3 plugs
Right, in the cylinder head...

Offline shpark2

  • Newbie
  • Posts: 27
Re: Fan Clutch
« Reply #10 on: October 04, 2007, 11:04:52 AM »
Gee...that would make too much sense, no?  :-[  LMAO  This is why I don't fix truck in mornings!

Offline DnStClr

  • Senior Member
  • ****
  • Posts: 1809
Re: Fan Clutch
« Reply #11 on: October 04, 2007, 11:58:33 AM »
Could be that cold Canadian weather. Did you say it's 35 degrees in the morning?!
Don
87 Chevy Silverado

Offline shpark2

  • Newbie
  • Posts: 27
Re: Fan Clutch
« Reply #12 on: October 04, 2007, 12:25:22 PM »
Yup, we had a good frost a few nights ago - leaves are falling pretty hard now.  It was just above freezing this morning, truck still starts like a gunshot - thankful for that. 

Question: When I have my choke (electric) set for 0 Fahrenheit conditions (average winter weather), I want to make sure that I have the choke rotated clockwise to tighten up the holding force of the bimetal on the choke linkage and the choke valve flapper thing on top of the primary barrels? 
When I rotated my choke clockwise it made the choke valve harder to open with my finger, and when I tapped throttle it now snaps shut (instead of before, it kinda didn't close whatsoever)