Weird Humming

I took my jeep out to wheel a while back, and went over some pretty big potholes at high speeds. After this, I began to get this low hum when accelerating over 45mph, and when I let off the gas around 35mph, there is this rumbling tumbling sound. I replaced the motor and tranny mounts, both were shot. I took the jeep for a test drive and there was this pronounced bad vibration, so bad it shook the whole jeep when accelerating. The vibes got a lot worse. I took the front shaft off and I was able to drive it around, but I still have the problems mentioned above, the hum, slightly louder, at 45 and over, and the rumbling tumbling sound, slightly louder, letting off the gas at 35 and under.:huh: Has anyone ever dealt with this problem before? If so, what turned out to be the problem? What does this problem sound like? Any suggestions will be greatly appreciated.

89 Jeep cherokee 4X4

try doing the same speed but in a different gear. if it stops happening or gets worse its the drive shaft. if its the same its not the drive shaft.

this may or may not help.