Fan clutches...

[jmbrodsky@domain.elided]

     Binders,
     
        I've gotten quite a few replies to my thread on fan clutch 
     remedy, however, I think that 95% of you are missing the issue 
     that I am trying to solve.  Should everyone have to go buy a new 
     water pump in order to put a flex fan on, or replace the fan 
     clutch?  That's the issue.  Personally, I don't want to have to 
     take the water pump out and put in another one, just so I can go 
     from the heavy factory fan blade to a flex or lightened blade, 
     and there aren't NEW thread on type fan clutches avaialble.  What 
     I porpose would be a method for converting a thread on type water 
     pump, to a 4-bolt flange, that would allow thread-on drivers to 
     have a clutch and flex fan, without the hassle of replacing a 
     water pump, and it's only as hard as 5 fasteners to convert.
     
        Here is a breakdown of the conversion:
     1: Loosen 4 fan shroud 7/16 head mounting bolts.
     2: Use whatever wrench combo is convenient to remove faulty 
     thread on fan clutch and rigid blade assembly.
     3: Place removed unit on shelf.
     4: Thread on 'Joel Brodsky's adapter' and tighten with tool from 
     step#2
     5: Install flex fan and spacer, by threading the four bolts into 
     the Brodsky flange, torque to spec.
     6: drive.
     
     Total time for conversion, about 20 minutes.  I don't know 
     anybody that can do a water pump in 20 minutes.  AND this way you 
     don't have to take all the belts off, loosen the tesnion on all 
     your accesories, worry about the shroud, etc.
     
        The option exists in step #5.  If one wants to go with a fan 
     clutch, then it reads:
     5: Install fan blade from step #3, onto NEW Lifetime fan-clutch 
     (~$25 anywhere).  Torque 4 fasteners to spec.
     6: install fan clutch and blade assembly on Brodsky flange, and 
     torque 4 fasteners to spec.
     7: drive.
     
     OK, OK, so the second method takes 25 minutes.  C'mon guys, do 
     you really like doing these water pumps this much?  At least with 
     my adapter, you could, conceivably, be out in the country 
     some-where and have a water pump fail, and be able to use EITHER 
     pump if one were supplied off the shelf.  I plan to carry a 
     spare, I already had to use the spare from my scout.
     
        Not really due to my truck staying cold, but more because the 
     entire rotating assembly now, is mounted rigid: Heavy factory fan 
     blade, thread on fan clutch which has been rigidized, AND the 
     skinny little shaft (3/4") is bearing the entire rotational 
     inertia of the set-up.  What this means is that every time you 
     start or stop, the shaft is required to be accelerated more, and 
     can fail, like Hi-Po Chevy and Ford water pump shafts fail.  Tom 
     H, ever had this problem?
     
        Try this if you have some chalk.  Take a stick of chalk, and 
     place your fingers at one end holding it with your thumb and 
     index finger.  Place the other end of the chalk in your other 
     hand, also holding with your thumb and index finger.  Now twist 
     the chalk like a bolt and nut combo.  The chalk will crack on a 
     helical pattern due to tension and shearing in the shaft.  This 
     is precisely what will happen to the fan clutch shaft or water 
     pump shaft if it is too thin and fatigued or overloaded.
     
        Let me know what you think,
     

     -Joel Brodsky
        www.physics.arizona.edu/~jbrodsky

         '76 IHC Scout II Spirit 345/tf727 RE8000, Cibie40s, custom 
                rear tire rack, 6 different color body panels.
                Not much sport, all utility.
         '75 IHC Travelall 150 4wd 392/tf727 Hummer brush guard, 
                3/4T rear springs, Hella Rallye 2000s, Con-Ferr 5x7,
                Class IV hitches front and rear, 3" Exhaust.
                1st Place, Rocky Mountain IH Rendezvous,
                3rd Place, Tulare IH Western Regionals.
         '74 IHC Travelall 150? 2wd 392/tf727 "The 'new' one"
                Factory AM/FM, Cruise, Tilt, AC, Captains Chairs,
                Rblt: Alt, carb, fuel pump, ps pump, water pump, dash,
                seats, rear door, starter, master cyl, what could be left?