transmission trouble

[Marc Knipper]

Have a 92 with a 4L80E transmission. It doesn't want to shift into overdrive. Is the tranny screwed or is it electrical.. Help

[ED MEEK]

my 93 had that problem, and it was a bad throttle position sensor. it is easy to change. i would pull codes first.

[taznj63]

I had same problems with mine and turned out to be solenoids in the trans. They get gum'd up and stick. Would be good idea to flush trans then change all solenoids in trans to get all old fluid and particulates out. Had this done to mine at 145,000 miles and it is like a new trans.
Check Codes as they will tell you if sol's are sticking.