really stiff suspension

hey my 81 toyota pick up 4x4 has really stiff suspension. i assume there is somthing wrong with the absorbers but i'm not familure with what could be wrong with them. the front has very little give and the rear has none at all. driving on even a moderatly bumpy road is dificult. even 4 people in the bed jumping doest move the suspension at all
so any sugestions...thanks