Rear hatch now harder to close

Hi all,
I've had my 2010 for about 17months and 16k miles. Early on, I remember that I was able to easliy close the rear hatch by just lightly yanking down on the handle, and gravity would do its thing. However, these days, I need to pull down much harder to get it to close in one try. Should I try to lube the hatch shocks and hinge? Or do I need to clean them first somehow? Just a minor annoyance. Thanks for any advice.

rich