Pre-assembling unit for a motor vehicle, vehicle door with such a unit and assembling and disassembling method of such a vehicle door.

The device has a window frame (1), a side window pane guided in the window frame, a window lifting mechanism (2) and a unit carrier (3) reversibly connected to the frame with a wet side (N) and a dry side for separating the door box into wet and dry regions. At least one attachment arrangement connects the lifting mechanism to the unit carrier and is removable from the dry side of the unit carrier. Independent claims are also included for the following: (A) a motor vehicle door with an inventive unit (B) a motor vehicle door mounting method (C) and a removal method for a unit carrier.