Hey guys looking for some help or be pointed in the right direction. I have bad vibration when the car starts moving in low rpm range. Usually when I take the foot off the brake and slowly hit the gas the car starts to vibrate. I initially thought it could Bethe engine but I have not noticed any codes.
The car runs smooth when you are driving or when you are above 3,000 rpm but below that it has vibration.
I recently had my transmission swapped out. I looked over all the bolts on drive shaft and the transmission itself and they are tight. The tranny mount is also nice and tight.

What else could it possibly be any advise would be appreciated

 

Check engine mounts. They will do that. My friend had a busted one in high school and it vibrated badly at low rpms but was fine at higher speeds