Help---expensive sounding CLLLank!

[Gene Halpern <morgantruce@domain.elided>]

It is fortunate that you rarely hear the kind of noise that I am describing:  a
CLLLLANK that sounds something like a tooth of a gear skipping or jumping. It's
the kind of sound that makes you suspect that the end is near for my 1966
International pickup, 1100A, 4x4, flatbed, with 3/4 ton rear end.  I'm
worried...and I'm not even sure where the noise is coming from.  It seems to
occur when attempting to climb a hill in 4WD---although it also happens in 2WD
with less frequency.  It happens every couple hundred feet of travel---unrelated

to engine speed or wheel rotation.....more in tune with any strain the truck is
under (climbing or turning).  With the windows down, I cannot  say the noise is
coming from a particular direction---which makes me suspect the rear axle,
transfer case, or transmission.  It is sounds "expensive" enough that I don't
feel comfortable trying to reproduce it over and over in an attempt to zero in.

Any thoughts, words of encouragement, or sympathy is appreciated.    :-)

Gene Halpern
West Virginia

PS:   I LOVE this truck!