Unknown condition/situation. Under 40 degrees outside temperature, at 15-20 mph and 25-32 mph a high pitched whine which will increase in pitch until the upper end of the range where it will abruptly cutout. The whine is not above my hearing range, but actually stops. It will not repeat in 3rd gear or overdrive. Temperatures generally above 40 degrees, it will not whine even if the engine is cold. Have had the universal joints replaced 2-3 times and now with grease fittings, and greasing them. Cannot currently track down the sound or cause for the sound.