Sound driving up hill. 3rd-4th gear

New to tacomas, have a 2004. When in driving up hill in 3rd and 4th gear I get a thudding sound. Not sure if it is normal or what. So hoping someone can tell me the typical sound.

 

Could it be the start of a rod knock?

 

Need more information. Motor, rpms, vibrations, where does the sound come from, are you supercharged? Can you replicate the sound in different situations?

 

It is the 3.4. The sound is coming from by my feet Area or the exhaust.
I have a video on my phone that has the sound. Hard to explain it it's a little bit of a rumble around 2000rpm

 

its probably not rod knock if you can only hear it in a certain gear and don't hear it throughout the rpm range. Are you sure you aren't just in too high of a gear for the climb and its just bogging down? Im assuming you aren't new to manual transmissions though...
post the video on youtube and link it here