the vibrations are driving me nuts, I got a new center support installed, bearing, rubber donut, everything....helped a little bit, manual trans 5 spd...I have some movement on the shifter when letting the clutch out when I hit 2nd gear...(this is still the same no better or worse after repair), mechanic guy said trans mount looks good, I have read and read on this driveshaft vibration, and I thought i had it pinned down to that center support, but apparently that wasn't it, what's next....drive shaft is tight going into the support (no play), and no play where it meets the trans, I have noticed if I grab the drive shaft and pull on it near the rear-end...it has maybe 1/8 1/4 inch of play, could it be the u joint back there....that is what I am thinking, or some bushings somewhere....please help if you can...center support was def. bad rubber was all deteriorated, and the bearing spewed its grease all over the place down there...also maybe thinking the drive shaft needs to be balanced....vibrations all are but non existent above 40 mph....maybe something else is bad and caused that bearing to have too much of a load is what I am thinking maybe....so if anyone has had this annoying vibration below 40 and real bad at like 15-0 please help me.

thanks