adjust stearing gear or replace??

[rydafoo]

my 1987 gmc s15 has a lot of play in the steering and ive already replaced idler arm, center link, and berrings so i assume its the steering box or gear if thats wut its called. ive been told by some that i can just adjust it to fix the problem but others say if i do it would just lok up when i turned,without the proper sevice manuals i wouldnt know how to adjust it if it could be, id appreciate any input, thanks