yes you should keep them level,because if you dont,it will wear the bearings.
Could Not answer any better than ironhand 100% dead on the money Good Job, may have thrown in that the ter for allighning the drive shaft is called Clocking... LOL
It is important to keep the bearings square with the drive line. The whole point of having the bearings to support the multiple piece drive line is so that the shaft doesn't need to be absolutely level with the frame, or to be absolutely straight from the transmission to the differential. THE ONLY CRITICAL angle is that the mating surfaces of the transmission and the differential must be within a tolerance of 1-1/2° of each other. The OTHER critical issue is that all of the bearing bosses must be square with each other. If the number 1 joint is positioned at 12 o'clock, then numbers 2 3 must also be at the same index or the driveline will grow under load and at speed ( 40 MPH) and will exhibit a server vibration. Good Luck
