So I parked my jeep the other day on a fairly steep hill and when I came back out, the think has rolled probably 10 feet and is just easing down the hill!!! What could cause this???

 

Is the front driveshaft in it? With the 249 and no front driveshaft, Park will not work properly or not at all.

 

No. The viscous clutch went out so in order to keep it drivable, I dropped the front shaft out. Why doesnt the park work without the front shaft?

 

The park lock is in the transmission and locks the output shaft. Without the front shaft, there's nothing to stop the front shaft yoke from spinning an allowing the rear shaft to turn. Fix your E-brake or chock it.

Funny story. A friend had an old Ford pickup with no e-brake so he'd just park it in gear (manual trans). On a slope, it had so little compression, it would chug downhill very slowly so he carried a couple of chunks of firewood to chock the wheels with.

 

Makes sense I guess. Im looking into the ebrake, but for now its a couple 4x4s.

I had a buddy that had a eclipse that was manual. He always just parked it in gear. We were hanging out at somebody house and their drive way is pretty steep, well we all parked, his head gasket blew while it was just setting there ( I would assume from the constant pressure maybe?) and it rolled into the guys house.