I'll be posting this question to Cardinal Flyers later on, but for now just wanted to relate what happened today and ask a couple of questions. I was going to make a fuel run to a field about 50 nm south, but upon takeoff, when I raised the gear handle... nothing. I'm sure I heard/felt the gear motor running, but when I glanced at the indicator after a few seconds, the green light was still on, and the main gear was still down. (On the Cardinal, the green light goes out when the gear starts to travel, and the yellow only comes on when locked in the up position.) My first instinct was to reach for the handle, put it down, and try again as this had happened once before, about 7 years ago, and never happened again until now. But there was resistance in the handle for a few more seconds. Finally I was able to put the handle down. Once again the feel of the gear motor running, but of course the gear was down, the light was still green, and nothing happened other than the motor stopped after a few seconds. So I scrapped my planned fuel run, flew the pattern and landed uneventfully. I asked the local mechanic what he thought, and then decided I would try another lap in the pattern and see if the problem was a one-time event, like 7 years ago. But first I wanted to make sure that I could pump the gear down manually in case the gear motor was faulty and could only manage to raise the gear, maybe part way. We checked the hydraulic fluid, and then tried to extend the manual gear pump handle. Here I was in for a shock: the thing was absolutely stuck. I could not budge it at all. Steve was able to twist it a bit, and after applying a little WD-40 was able to pull it out an inch or so, but no further. So I scrapped the idea of a lap in the pattern too, and taxied back to the hangar ramp. So my questions: 1) Do any likely causes come to mind for the failure of the gear to come up? Steve thought the motor was likeliest, but I wonder, since I definitely heard/felt the motor running, yet the green light never went out as it would if the downlock had at least released. So I wonder if one of the downlocks might have failed to release. 2) What in the heck would cause a manual gear extension lever to freeze up like that?? It was definitely checked (and worked) at last annual in May, 2017. This is a 1976 177RG.