Tension? Are you referring to it when it opens and closes? meaning when you have it open all the way up that it slowly closes itself?
How old is the laptop? Is the laptop under warrenty? Might want to call the manufactuer to see if your warrenty will cover fixing the tension in the laptop.
I have no other adivse im sorry, Maybe someone else coming along will have a better suggestion.
NeoStar
BTW Welcome to TechIMO (TechInMyOpionion)