The parking pawl ratcheting on the park lock gear indicates that the transmission output is turning even though the vehicle is stationary. This means that something downstream of the transmission is disconnected e.g. an issue with the transmission output shaft, transfer case, propshaft(s), final drive(s) or driveshaft(s). Do you have access to a ramp where you could check if either propshaft or the driveshafts are turning when in D or R with the brakes applied? The spline between the front propshaft and the transfer box is a common failure mode on the E53.

Phil