What year is your truck? Is it automatic 3 speed or manual 3 speed with a granny low gear? Its an easy fix either way, but I need a little bit more info so I can give you the correct procedures. /K&K

Keith & Kevin's Repair & Restorations. Its 3 speed with granny gear. And its a 76

Prefect its possible when the Top Loader Shifter was installed the shifter ball (Bottom of the shift rod) and shift socket rail (Inside the transmission) did not mate or it was knocked into 3rd and shifter ball has the shift rail socket pinned. Its very common condition to miss the ball and socket mating during installation and be stuck in a gear. 3rd gear is the easiest gear to get stuck in. You will have to remove the shifter assembly and take a look down inside at the position that the shift rail and socket are in. This part is done inside the cab. Gently move the shift rail back and forth or side to side till neutral is found and 3rd gear is released. This may take a couple of attempts but being patient here can pay dividends. I can not stress enough be very gentle when moving the shift rail inside the transmission back and forth to find neutral again. You should hear and lightly feel a slight pop when the gear change happens once neutral is found. Those are beefy transmission so I doubt any damage has been done other then you are bound up at the shift linkage. I would get the rear end up in air so you can turn the wheels freely to test for neutral while moving the shift rail inside the transmission. Again be gentle when testing for neutral via the wheel test. This method is the least abrasive way to test for neutral, either the drive shaft spins freely or it does not .>>keep moving shift rail inside the transmission

I tried moving the pin and ball there but it didnt work

Does your SM465 have P.T.O. covers. You might be able to use the P.T.O. cover access to knock it out of 3rd and back into neutral and finish install of the shifter that way. This way is messy and will require new gear oil and side cover gaskets. I was looking at some old books I have and it seems to me that you might be able to use the shifter as well to knock it back into neutral. Don't install the shifter as far as the final twist lock goes but insert the shifter back into the hole in the third gear position and see if you can get it back into neutral. Its kinda like using a coat hanger to get a car door open. The shifter itself is large for one main reason leverage. Its going take a similar force to get the forks back into neutral from third. Other then that I hope you won't have to remove the Top Loader Forks Section of the SM465 to correct this issue. /K&K