My gearbox gets stuck in 4th, if I cruise to a stop with my foot on the clutch. But if I gently slip the clutch until the gearbox is trying to push the bus forwards, it will pop out of gear again. I know at least my main bearing is able to move forwards about 1mm, as that much is worn off the nose cone. I am going for the Bears treatment for my gearbox - call them to tell you are sending it, send it DHL without oil, well wrapped up.. Says it will take about a month when it arrives. Give me time to do some painting and patching up above it.
When its wedged, I can feel the spring tension in the linkage building up. It doesnt feel nice. If I cruise to a stop in 3rd it doesnt jam up, or if the box is in neutral.