its a 1999 ram 1500 crew cab with the 5.9 i believe and on occassion when i go to accellorate i get a vibration probably coming from the tranny or rear end but once that happens if i let off the gas and try again it may go away...... any suggestions?

 

have you checked your tranny mount for cracks.
Anytime I have had this problem it is a bad trans mount.
pretty cheap and easy to replace.