83 Suburban K2500 Transfer Case vibration & noise

My Suburban K 2500 6.2L Diesel was parked for over a year, The rear drive shaft removed. but the trans/transfer case holes were covered. Yesterday, I installed the drive shaft and drove a few miles, all seemed well. Tonight after a 30 mile round trip excursion it began to have a steady vibration in the front and there was a roaring noise that increased as I drove back home. I originally thought it was road noise. Once home, I put it into High 4wd. It engaged, but would make a loud "pop or bang" sound from the right front, but still stayed engaged and would move forward and backwards. I am not very familiar with the working of the 4wd system and need information from those who have more expertise than I do on servicing the system properly. Thanks for any help and advice.