I'm getting that exact same "clunk" noise. Sometimes in drive just starting off, sometimes when it shifts, or down shifts, going into reverse and back..Had the tires off and looked at the mounts going into drive / reverse nothing stands out. but not
much weight on the system on jackstands and no tires....No ideas...Transmision craddle, lower mounts, upper torque struts(mounts) ? No clues....