one of the bolts that hold the pitman arm shaft adjustment cover goes into the gear box for filling. remove one of the bolts one at a time and insert a wire or smilier thing into the hole and see if goes though. when it does use a small funnel and add 90W gear oil to the gear box. it is a slow process because of the small hole. take your time , it will be messy. you might want to check web sights and search out for the amount to add. just type vega gear box, and see what come up.