Took my Ram out last nite to get groceries with the snow we had & the blustery wind/cold that we have been experiencing. Roads where still covered in good amounts of snow from drifting soo I decided to take the Ram in signature instead of my Acura. Now, the average high for the last two weeks has been mid 20s & with the wind chill -- in the single digits or below zero. I used the truck in the summertime to gather some fire wood at my one buddies house where there was lots of mud to go & from. The Ram never made a noise then or before. Like a whining noise you would hear being in low gear or low 4wd mode im assuming. I had it in high 4wd mode at all times. My fill in the transfer case is Mobil One LS 75W90 gear oil as recommended from a mechanic friend years back to help with that big chain slugging around. Like I said, never made that noise before when I did use it in past winters. I was only going about 45mph max. As soon as I put it back into 2wd mode -- the whining went away completely. When I did engage the 4wd mode to start off, I was stopped & had it in park like I do any other time?? What could or would make that whining noise? Being super cold for a long period of time or what?