electric window motor

[Paul w]

I have a 69 R/T SE and my driver door window lift motor is having a hard time doing what it should do I have fitted the motor 3 or 4 times and checked it out   it works fine but wont lift the window. I have used silicon spray on the guides but still nothing. is there a way of re clutching the motor as there are three round rubber bushings in the motor witch seem to have gone soft with age can you refit new ones and if so how firm should they be as I think they are the motor window stop clutch   HELP

[Tilar]

Are they actually used as a clutch or are they used to cushion the sudden stop and keep the gears from stripping?