c-6 transmission question

I had a problem with my '89 F250 transmission. It seems the kickdown lever that goes through the side of the transmission housing is binding somehow and after using full throttle the lever stays in the kickdown position. I've checked the cable and it moves freely, the binding is in the lever. If I manually return the lever to it's normal position, the transmission shifts normally. I've looked at a junk transmission and seen how the lever strikes a plunger on the inside so I can't figure what could cause this binding. Any ideas before I take it apart?

Bent or rusted shaft going through the transmission case? Or, it could be the throttle valve binding in the valve body. You could leave it unhooked and manually pull shifter back to second if you need passing gear.

Spray the cable at the top with lubricant....it's most likely just hanging up.....assuming of course nothing has been damaged.