Selector rod, sticking in neutral and jumping out of gear back to neutral

[sasu]

My mechanic told me that just one botched shift from first to second can be enough to cause this problem. In the transmission there are pins on the gears that enter holes in another gear. Those pins have a small shoulder. If that shoulder gets rounded by a hamfisted shift, the pins tend to drop out of gear. The damage to the shoulder is so small that you have to look at it in certain light to see the change.

This is second hand information so no guarantee of accuracy.