I recently put another motor in my 2003 jeep 4.0 I took it out of a 1999 and used my trans well it runs and shifts good but after driving it for a hour it sounds like somethings hitting the dust cover when its in gear its loud and when i put it in park it a faint sound but sometimes not at all but it only does all this when it warms up can anyone tell me what it is its driving me crazy

 

Check the torque converter bolts and the bellhousing bolts for being loose.