@KRoyal has the right idea about the sled as it has a good length of friction surface. Here are a couple pictures that show where I grease. It’s kind of hit and miss at first where the friction points are, so you’ll see grease all over on mine. Some unexpected places show up when you grease the whole thing and cycle it a few times.
There could be more places. I cycled mine hundreds of times over the winter when I couldn’t go out; it was pretty rough at first until finding most friction points. Finding them on the sled made a big difference (see red highlights on first picture).