If you have an older vehicle, the door may sag a bit when you open it. But it doesn’t have to. The most common cause is a set of worn out door hinge pins and bushings. Here is an affordable way to fix it that won’t take you all day.
Even if there is just a small amount of looseness in the hinge, amplified down the length of the door ends up being a lot of movement. To correct it, run to a local parts store and pick up and pick up a set of door hinge pins and bushings. Then all you need to do is install them.
First, drill out and grind off the top of the pin. Inside the pin is a set of brass bushings and after years of opening and closing your door they can wear out. Using a punch and chisel, collapse the side of the bushing and pound them out. With the soft brass bushing in place, top it off with a washer so it doesn’t get distorted as you press it in. Do the exact same procedure for the bottom.