Q: Engine shaking when driving and put into gear.

Hello, I've recently been have some vibration in my engine and also when I go from 2nd to third gear my engine would bang into third gear. Also when I'm driving for a long period of time and I put my car into reverse the engine has banging noise from it shaking. I recently changed my dog bone mount, passenger side mount and driver side mount. But it still it doing the same thing, so do you have any idea what the problem could be because I don't wanna make anything worst. I've notice while changing the dog bone mount that my subframe(I think its called the subframe) is loose while the wheels are off the ground, so I'm not sure if that could be the problem to. Please let me know!
My car has an automatic transmission.