I've got a '94 S10 pickup 2wd. After about a half an hour of stop & go driving, it becomes harder to shift. Sometimes I'm really fighting to get it into and out of gear. If I shut the engine off, it will shift and then I have to do a quickie start. I've had two mechanics check it out and neither knew what the problem was. I thought it might be a sending switch or sensor that might be the gremlin, but after studying the wiring diagram I saw nothing to indicate that was where the malfunction is. Has anyone else ever had this type of headache, and what was the remedy?