why am I stuck in park

[smell my dirty poodle]

I need some advice. My 86cj 7 258 i6 with a 3 speed auto transmission sticks in "park" when parked on an incline. It also sticks in "drive" when climbing(dangerous!) . As far as I can tell the linkage is fine, I think its internal.
Heres the question. Whats wrong? How can I fix it? should I just get another transmission? some body must have had this problem before.

 

[cewtwo]

There is a cog, gear, or key type thing that slips down and locks the transmission. Yours is obviously broken. Take it to a transmission shop.

They'll give you an idea of what is going on. I don't beleive it is user serviceable.

But heck! I've been known to be wrong!

 

[smell my dirty poodle]

hey thanx for the help. that makes the most sense so far.

 

[TwistedCU]

auto transmission sticks in "park" when parked on an incline.

Are you setting the E brake before putting it in park on a hill? If not the weight of the Jeep is holding it in park

Sorry if that was obvious, but I had to ask.

 

[smell my dirty poodle]

Yeah, setting the e-brake is the only way to keep it from getting stuck in "park" on an incline. However I also get stuck in "drive" when climbing. I am not able to shift to "reverse" should I need to retreat (dangerous). If it does get stuck in "park" I rock it back and forth to take the pressure off the transmission if that doesnt work I then have to have someone try to shift to "neutral" as I bang on the arm that attatches to the splined post that comes out of the trans. this is why I dont think its a linkage issue. its stuck in the transmission. thanx
fellas I hope that clarifies some things. let me know if you have any other thoughts.