Concerning Sycro Viscous Couplings:

        I made the original post about rebuilt Viscous Couplings (VC).  Yes
they do go bad--though I cannot vouch that any whine is associated with
it--that sounds to me like a front diff problem.  To test the VC, jack
up one of the front tires and try to turn it--should stiffly resist
turning, to the tune of about 25 lbs torque on an old style torque
wrench, placed on a lug nut.  If the front tire rotates freely, the VC
is bad.   Rebuilt VC from German Transaxles of Bend ORegon  (1-800
892-4327), $600 plus refundable $300 core charge.  Good deal.

Hope that helps,  Joel Skousen