Each of the BMW window regulators is designed to smoothly take your door windows up and down without them coming displaced. The window regulator is the section of the window moving device that actually is attached to the glass via several bolts. This portion can not been seen unless the door panel is removed.
With the removal of the hand crank and being replaced by an electrical motor, the windows in a BMW are now moved up and down by the window regulator with the simple push of a button. This is standard equipment for all makes and models of BMW today. The distance the window travels is set by sensors on the window regulator so too much force will not be applied to the glass when it reaches the full down or up position and there is no chance of failure of the glass or the regulator. The part most often needing replacing in a BMW window regulator is the electrical motor. The slides and end channels that keep the window in place should last the life time of your vehicle if it is not involved in an accident. If the window appears to be moving irregular the slides and tracks the window is placed in can be greased. This is the only maintenance for this auto part.
To inspect or replace the window regulator of your BMW, the door panel must first be removed. With the window in the up position, a brace must also be put into place to prevent the glass from coming down and allowing the technician to work in this confined space. Once the part is replaced, the brace has to be removed for the window to function properly.