Name that noise......the 4k edition

[Gfbourcier@aol.com]

List,
We had out first cold snap here in Maryland this week and the 87 4kcsq is 
making a new noise.  It sounds like 3 or 4 mourning doves are stuck 
underneath the vehicle.  It is not RPM related, but presents itself when 
accelerating from a stop until I reach 40mph or so.  With windows open and 
head outside (like a dog!) you cannot hear the noise.  Inside it is quite 
loud, and does not make any noise at highway speed.  It is not the wheel 
bearing "roar" that I am familiar with and does not cause any vibration or 
drivability issues.  Should I suspect that the center support bearing for the 
rear driveshaft is drying out slowly and I still have time to save further 
damage?  Is this bearing serviceable?
Thanks in advance for any and all replies,
Gil Bourcier
Columbia, MD USA
87 4kcsq-88k mi.-mine
90 V8Q-130k mi.-hers