on the way home from work. Something made a loud pop as I made a right turn from a stop onto heavy traffic (so I wasn't gunning it). My initial thought was that I ran over something, but then the car started shaking. I switched neutral at stops and it still shook. I was only a mile from home so I went and drove on. Once I past the heavy traffic, the car had decent pickup and tranny seemed to be shifting ok.

Got home, popped open the hood started the car again. It was calm for a little bit, then the fans kicked on and it started shaking. Do I need to replace the whole fan assembly?

 

I found two fan assemblies on O'reilly site. One is listed as a dual radiator and condenser fan assy ($210) and the other is just listed as a radiator and condenser fan assy ($199)? They look a little different. How can I tell which one I need?

 

I went and did another little test. Turned off the A/C and started the car. and let it idle for a bit. Everything was smooth until I turned the A/C on. It started shaking just after that

 

You could have a leak in the system and there could be loss of lubricant/coolant.
You might want to have the system looked at... and I would suggest avoiding use of AC.

 

Why would you figure that the radiator fan(s) need replacing when the engine it the thing that is shaking? The load from the A/C compressor will reduce the idle speed of the engine unless commanded to compensate by the computer, which pokes the IAC to increase idle rpm. If the IAC is not working, you will likely get shaking or stalling when the A/C is engaged.
I would check the IAC for function before even looking at the fans, but to each...
tom