After a lot of attempts to bake correctly I have this result. But as and before I have a tiny little dark areas. I tried to clear seams (if this areas laying on between two meshes) and after unwrap objects and pack UV and save it. After I have changed margin in baking options, and from one attempt to another I have different result (dark areas transform to other positions), but no one is clear AO map.. Face orientation is correct and I haven't seen the stretches on the UV (there are simple forms of tank body). Can you advice something to check or what would you do at first with areas?
The problem was solved by increasing the margin of UV pack and baking once again for movable part of the tank and non-movable.
