Thoughts please

Can someone really good with Rubicons to give me there opinion? I bought a 06 Rubicon 500fga not running as a learning experience and have done the top end and gotten it going. Now my problem is that when I drive in 1st and 2nd there’s a weird sound but I can’t hear it in the other gears. It doesn’t hop or slip and no filings in the oil, it rips like it should but sounds somewhat like it’s in-between gears or something similar. Do you think it’s clutch, a bearing or just transmission shitting the bed?

Thoughts please

Can someone really good with Rubicons to give me there opinion? I bought a 06 Rubicon 500fga not running as a learning experience and have done the top end and gotten it going. Now my problem is that when I drive in 1st and 2nd there’s a weird sound but I can’t hear it in the other gears. It doesn’t hop or slip and no filings in the oil, it rips like it should but sounds somewhat like it’s in-between gears or something similar. Do you think it’s clutch, a bearing or just transmission shitting the bed?