Transmission

I have a 1990 chevy van. It will not go into high gear. Feels like it wants to, but will not. Curious if anyone has experienced the same. Didn’t know if it was a linkage prob or what. Heard some things about air hose or something…I need some help. Thanks





?

Does this van have a switch to disengage the overdrive? That is the first thing I would check.