AW4 shaking, torque converter or flexplate ?

My sons MJ with a 4.0 and an aw4 is shaking badly. It will shake worse under load but also shakes in nuetral or park at certain RPMs. The vibration goes away when the torque converter is dissconnected. The flexplate has a noticable wobble which is worse when the torque converter is unbolted. Could that be the cause of the vibration or is the torque converter more likely to be the problem ? something else ?
Any ideas?
Dave

I've read the flex plates crack. And if yours does not run true with the converter off then you've found the problem. As I recall reading it cracks around the bolts.

JoBo

the flex plate has been known to crack completely around the crankshaft flange.. with only the engine and torque convertor's close proximity to eachother holding it together.. i'll bet when you pull the tranny the outer section of the flex plate will come off and the flange still be bolted there.. i believe eagle had this exact thing happen on his "montana XJ" last year..