I have a o1 Taco, std cab 4x4 w/98k miles. Within the last two months it would pop out of 4th gear while driving. Pushed the clutch in and put it back in gear. Go a few miles and it would do it again. A couple of weeks ago it started doing this in 3rd gear also. I talked to a couple of tranny shops and they were stumped. They wanted to pull the tranny and go thru it to find the problem and replace the clutch (working good) as long as it was apart. All for approx $1600. Long story short, a friend sent me a U tube regarding this problem. I replaced the shift lever seat and bushing for $20 and 30 minutes labor.