Putting a new engine in my 01 Neon and made an oops. I removed the 'E' clip on the shift lever into the transaxle, the shaft drop into the transaxle almost to the point that I was not able to grab it and pull it back up...almost. I was able to pull it back up and put the 'E' clip back on but now the transaxle will not go into park. What have I messed up and how do I fix it?

I suspect something internal but I have no drawings of what the insides look like. Any suggestions, theories, drawings etc. would be greatly appreciated.