My 2003 Jeep Grand Cherokee drives and reverses and shifts fine, but will not stay in Park. I have to use my emergency brake to keep it from rolling. What could be wrong?

one of two problems, first( cheep fix)your linkage could need adjusted #2 you have slamed it in park one to many times while car isent fully stoped and striped park out of your trans(exspensive fix)

yea...I'd say that your parking gear is gone in your trans.

All of those could be the problem. You need to also check for any service bulletins or recalls from your Chrysler dealer. I highly recommend looking on the internet for any bulletins for your Cherokee. Chances are that if you found something that matches your problem, you may not have to pay anything for that repair as it would be covered under Chrysler warranty. The same thing happened to me on my 1994 Dodge Caravan (with warranty expired) and I found what I needed on the internet, printed the results and got a free replacement transmission and free car rental through Chrysler with no hassles. Good luck! //C.O.

Your parking sprag has broken off.