The 99 is the same hinge.Your pins and bushings are worn out,happens to all the C/K's with high miles.you need to get them at a GM dealer,most have them in stock,there are 2 little bushings,and 2 big ones.Get 2 new pins and 2 locking clips too.Ive done a bunch of them,I masking tape the edges of the fender and door,on the side your doing,just in case they touch when removing them or reinstalling the door,the support the door with a floor jack or jackstand,i use a block of wood on the jack,so i dont hurt the bottom of the door.You need someone to hold the door,while you drive the bottm pin,up from the bottom,and the top one down from the top with a small hammer,There are little one way clips on top that will popo off when you do this,catch the door spring too,as it falls off when you release the top hinge.you are going to have to have someone steady the door while you pop out the old bushings and put the new ones in,after that,wipe some grease on them and the pins,line up the door,and put the new pins in.If the clip isnt put on the top one,it will creep out the bottom,eventually,destroying the new bushings,so make sure its clipped.I drill a small hole in the top one and put a cotter pin in it,that way itll never fall out,I dont have great luck with the clips,the bottom pin is held in by gravity,it wont fall out if you dont clip it.Be careful,the big loom of wiring going to the door has its liits,dont try to set the door down,just slip it away enough to replace the bushings,slide it right back on.The spring that goes under the top bushing can be put in if your good with a py bar,or buy the tool from a Napa store.I use a pry bar,and it goes right in.If you loose track of where things go,just check the other side.Good luck.
