I am having trouble finding 4th gear with my 901 transaxle. I can get it from 3rd after going into 5th but I cannot usually get it after being in 5th and downshifting. 1st to 2nd is also a little vague. About 2 weeks ago, I found the set screw in the coupler was loose and I tightened that, which improved things for a while. But now I am having trouble again finding 4th gear especially.

Does anyone have info on how to adjust the shift coupler? Up to this point, I have just been eyeballing it and making my best guess at the correct adjustment. There must be a more precise procedure for doing this adjustment. Can anyone who knows the correct procedure please tell me?

Thanks!