[blucar]

In the text of your original thread, you stated that you accidentally pushed the second gear lever when you were installing the trans. The following info might be of value.
When I was a teenage we would play games with people cars, we would open the hood, grab hold of the shift levers on the column, pushing them down which would lock the trans, when the driver tried to move the car it could not be shifted with the lever, the levers had to be moved to the correct position from the engine compartment.
It could be that the removal of the side plate messed things up within the trans.