Sorry I didn't say that well. It is a manual turn to left or right. I have worked on many walkie stackers but I have never had one like this one where the handle when pulled down seems to be locked into place. It moves about a 1/4" inch in both directions and that is it.
Update: I believe water got in on the bearing. I pulled handle hard to the left and right and it broke loose probably some rust and has worked ever since. I use it around the shop everyday just to make sure it is fixed.