I have a 204 1/2 3500 with 6 speed transmission, and 74,000 miles. The heaviest load I have pulled is a small compact car on a car hauler and I occassionally use a 2100 lb slide in camper. I have a high pitched whine when very cold (single digits and lower) at about 25 to 35 mph and in lower gears. The whine occurs whether clutch is engaged, disengaged, transmission in neutral or in gear. Whine goes away after truck warms up and at highway speed. The pitch of the whine does not change with speed except that it goes away at highway speed. It got so bad at -13 the other day that i took it in to Dodge dealer because I was getting ready to travel across country. The technician diagnosed it as worn pinion bearing and the repair cost $1200. 00. I started across country and heard it again faintly several times early in morning when cold and first starting out. Anyone had this problem. Any comments would be asppreciated.