I got it!!! YEAH!!! Thanks to everyone, especially Miriam, for helping me with this mystery. I watched the YouTube video by the Archaic and the Arcane that deals with the tensioner with the Slant-O-Matic.
https://www.youtube.com/watch?v=UttHpnQy0xk I was overlooking one, very small detail that she explained. The spring has a small hook at the end of the coil that needs to catch onto the gear when reassembling. It's so easy to miss.
AA does some very good videos, BTW. This one showed every detail. I just want to know how she keeps such beautiful nails while working on sewing machines all day...LOL.
Now off to watch her video on testing the tension. Thanks everyone!
~ Cindy