Four wheel drive has not worked in a long time

This is my elderly parents vehicle. Four wheel drive has not worked in a long time. They are away on a trip and left it with me to do brakes exhaust and more. Putting it in Four wheel drive should light the indicator, engage the transfer case and the front wheels. Indicator not lighting, transfer case engages (i think) because the front driveshaft is locked, not free but the front wheels are not driven.
Suspected the actuator (i think it is just a solenoid), so we took it out. Used a test light and it is getting power. We were able, with effort and tools able to pull pot and push in the plunger, so we lubes it with some penetrant and worked it a bit. We plugged it in with out installing in the axle, and when put in four wheel drive it slowly pushes out with almost no force. I think we can push it back in while actuated. I am wondering if that is supposed to work that way or not. I also noted it gets very warm when actuated.