My 87 245 just started making a whining noise and I am having trouble identifying where it is coming from. Noise started when the temperatures here in Houston dropped down to the 50's or so. The noise sounds like a jet turbine spooling up. Starts at around 40 MPH, increases in pitch and volume as speed increases, and then tapers off and stops around 60 to 65 MPH. I would think a wheel bearing would be lower pitch and occur steadily. It doesn't clunk like a u-joint. I would think that the diff would whine all the time and be more consistent when it got warm. Is this the center bearing or is there something in the tail of the transmission (automatic)? Thanks for any advice.