Ok so if I'm reading correctly how everything all goes together then part 10 engages part 3 which is bolted to part 2. Part 2 moves part 12 back and forth to engage the pto. If I'm correct then it looks like part 12 has two groves in it. Could part 2 be in the wrong grove? Could there be a burr or something on the splines of the pto shaft that slide into part 12?
Edited to add: I looked on eBay and there are several good deals on factory Ford service manuals. Several combinations of owners, parts and service manuals. If you are going to continue to do your own service a factory manual is highly recommended. I&T manuals are ok but they never go into the detail that a factory service manual does. Search "ford 801 manual". I tried to find a pdf of a manual but the prices for paper ones are very reasonable. Just a suggestion.
After about a zillion attempts I put the pto In neutral, held the shifter and gently pecked the end of the shaft, it went in. Thanks for your help and heads up on a Manuel.
