Our 8440 is becoming very difficult to start up. It changes well in A, B, C, D. But it’s a pain to get into 1 & 3. Either it won’t go into gear or there is a high pitched screech. We put the two new shift cables.
Remove the transmission cover to make sure the shift cam has not come loose or the fork has broken. Timing is a high-wear item. When you say 1 & 3 it moves in 2 & 4 if so that’s on your 2-speed planetarium but it sounds like it won’t start. The trans has 4 ranges A, B, C, D. With 2 speeds and reverse in each range then those are doubled with the power shift planetary ahead of the trans in the hinge area.