I have no idea where you can download a free manual but I have a 1036. The machine does run on the loud side even when it was brand new. When I notice it's a bit louder than usual, I know it's time for a good cleaning. There are no instructions on how to oil the machine in the manual. I've kept mine running by doing the following steps. First I clean as much lint as I can from the top of the machine. Slide open the slide plate and remove the needle plate so you can clean the feed dogs and all around the bobbin case. Put everything back together and now clean from the underside of the machine. You will need a tube of Singer Lubricant grease
http://www.singeronline.com/lubricantgease.html. Remove the plastic base cover. You will notice two gears directly below the bobbin case. They will be covered with lubricant and lint. I clean them with a lint brush and reapply grease. I do the same to the other gears as well. Any spots that have metal to metal contact I oil with sewing machine oil.