Yesterday the noise got louder! I’ve checked every part under the vehicle and everything looks good! No play on the exhaust, mounts or any suspension part! My 1st thought was that my driveshaft is unbalanced... Long story short, before I rebuilt my engine I had taken it apart at my moms house and left it on stands, had to get my car from my moms house one day, I had the trans on still and needed to remove the trans for the tow truck to take the car... It’s was a last minute thing, and I forgot to mark the half shaft to driveshaft correlation... So when I got around to putting everything back on, I had no markings to go with in regards to connecting both back on in a balanced state.... From that day I would hear a slight thumping sound at every take off... I bought the car used and undeliverable so I’m not quite sure if the car already had the issue? All that being said would a unbalanced driveshaft cause the loud thumping/knocking/clunking sound? It’s only of take off... Initially your first thought would be that exhaust what’s causing it, based on how hard the sound is... But like I said, the exhaust is tight... I’ve never had a problem with an unbalanced driveshaft... So I don’t have the slightest clue to how one would sound unbalanced?