Modulated Fan Removal

["J. Michael Daugherty" <jmdaugh@domain.elided>]

     This evening I removed the old style(1) modulated fan from my '76 SII.
I don't have an official pump wrench but I was able to work a monkey wrench
between the pulley and fan to get to the threaded coupler.  The trouble was
that I couldn't figure out how to keep the pump from turning when I tried to
loosen the fan clutch assembly - yes, I knew that it had left hand threads
because I checked out the FAQ.  I could see there are a couple of slots in
the pulley casting but I couldn't figure out how to grip them well enough to
keep the pump from turning when I tried to loosen the coupler.  Is there
somewhere else to hook onto the pump shaft with another wrench?  Eventually
I sacraficed one of the matched pair of alternator belts and overlapped one
turn around the water pump pulley and took a turn around the steering gear,
broke the coupler loose no problem.  I was planning on replacing the belts
anyway so that really didn't matter to me, but is there a more elegant solution?
     I am thinking about making a pump wrench to put this back together and
for future use.  The monkey wrench worked, but it was difficult to get into
position and tighten with the fan blades still mounted.  John Landry's post
mentions a pump wrench with a 30 degree opening.  On an IH, is there an
advantage to having the wrench opening at an angle to the handle as opposed
to being in-line with the handle?
     When I got the modulated drive out, like Yank(2), I found that the
bimetal spring on the front of the clutch was covered with oil and packed
with dirt.  I cleaned all of that out because it may affect the contraction
of the spring.  It seems like the fan is always turning fast and moving
quite a bit of air.  Hot or cold, no matter how hard or fast I've tried to
spin the fan, it quickly comes to a stop after about 45 degrees of rotation
- does this sound like the fan is "locked up" for hot temps to you?
     BTW, the fan is a six blade aluminum unit and it is MASSIVE!  I've
changed a couple of electric fans where the brackets, motor and blades weigh
only a fraction of what just the hub and blades of this fan weigh.
     Thanks for your help, 

Mike

References:
     (1)Landry, John A., "Modulated Radiator Fan - The Final Story!",
ihc-digest v3 n283.
     (2)Yarborough, Yank, "Glue removal, Steering, Clutch fan", ihc-digest
v6 n143.