New to the forum. Have a 06 Rubicon unlimited with 60k miles. Drained trany fluid and replaced with Royal Purple. In the morning (or when fluids are cold) when I shift to drive and roll down the street...first turn (left or right) trany disengage. Consistently, it happens everyday since I changed the fluid (removed plate, changed filter). I Have to wait until fluid gets warm (i guess) and than it engages. Did not happen when I use regular ATF+4 (Mopar/valvoline). I don't experience any of that after the temp has risen. Once fluid is warm enough trany works great. Is it viscosity issue?