Pulled the transmission and was able to FINALLY see the problem. 4th gear is indeed the problem. The synchronizer is stuck so I am not able to wiggle the input shaft and slide into 4th. All other gears operate properly. Now, I can still move the shifter lever to neutral and also lock it into 3rd. When I have all three levers in the neutral position, I can turn the input shaft, and the output shaft turns with it, as it should. If the synchronizer has 4th locked in, would I be able to turn the input freely with everything in neutral? That has me stumped, but then I'm not a transmission genius. It would make sense if it was locked in because, as I initially wrote, when I tried letting the clutch out when it was in reverse, the engine started bogging down immediately showing something is locked..
Am I explaining this clearly enough? :chin:
I tried tapping lightly on the side (not the tooth) of the synchronizer with a small screwdriver and hammer. It wouldn't even wiggle, so I quit. Don't need to cause anymore issues. Anyone ever released a stuck syncro ?