I can not say about all models.. but on the ones that have the tool that looks like a screwdriver on the end.. That can happen ... The roof gears are ran by the screwdriver slot in the middle that runs the sun roof..... the nut on the out side adjust the clutch.. so the motor moves the screwdriver part.. (Over simplefied).. So if you moved the nut you may have loosened the clutch.. Tighten the nut and you tighten the clutch.. over do it and you burn the motor up.. Most of the time if the motor runs it just needs to be adjusted.. It has been the same from my first one on my 67 250S to my 85 300 TD.. and my SD's.. However my wifes 92 300CE has a plastic adjusting handle.. and I do not remember any manual way to run it.. But then only adjusted it and did not try to run it by hand.. I can not tell you about other years and models..

Ken