Well, i can't get my tranny into 3rd gear. It is an 83 GMC 3/4 ton pickup in case anybody wonders. I was driving the other night and it just wouldn't go into gear, and i haven't been able to get it in gear since. I can go through the other gears no problem, but not 3rd. I tried shifting into 3rd with the truck off just parked too and it still won't go. I'm thinking something in the shift rails, but i'm not sure. Anybody have any ideas?