4 speed od locked up

[b1964]

got a 4 speed overdrive in a 64 dart w/ 318. today while driving , it would not allow me to take out of 4th gear. i jacked it up and tried to move the 3/4 lever back into netural, no luck, i can get the car to move but only in fourth gear , with car off i can move shifter but will only go into 1st,. with all rods disconnected the shifter moves freely. not an expert on the 4speeds, and engine and tranny have less than 300 miles on them. anyone had this problem before?

 

[cudamark]

Probably the side cover interlock mechanism is bent or broken. I'd pull the cover and check those parts carefully. Will the separate links move with the shifter disconnected?