An update, in case someone with a similiar problem searches and finds this thread.
Since this is a more generic AC question, than it is a specific Jeep Commander question, I also posted it that www.allpar.com
forums. That should be a resource for everyone on this sight. Might NOT be as good for Commander specific advice, but if you've got questions or problems with more general things that all Chrysler/Jeep/Dodge have in common, like engine/trans/AC, etc, you can ask them there as well and get a bigger pool of knowledge.
Some knowledgeable people have confirmed for me, that too much oil in the AC system can cause these noises.
But, first thing recommended is to do an accurate measurement of the high/low side pressure of the AC according to the procedures in the FSM and check those pressures against the FSM specs. This is best indicator to tell if the system is over/under serviced with R-134a or if there is some sort of malfuntion with the parts in the AC system. Once that all checks out, then the following are possible causes.
To much oil in the AC system (I know there is at least 1.5oz more than spec in the system, either Four Seasons instructions for the rebuilt compressors is bad advice or the instructions are so vague, I misunderstood them). I guess the lesson is, if the spec is 7.5oz of oil for the system, then have 7.5oz of lubricant in the system, NOT more or less.
There is no oil drain on the AC system, I will have to open the lines to drain some oil (remember you have to properly remove the regrigerant from the system before opening it) If you open an AC line under pressure (and they are under pressure even when the system is off) it will burst open (with risk of injury) and tons of refrigerant will rush out spraying everywhere carrying lots of the oil with it, and then you have no idea how much oil is left in the system. And everytime you open the lines, you're suppose to replace the filter drier, which the filter drier should have some trapped oil in it that you have to replace when installing a new one. I have to look up the specs for the trapped oil, but just replacing the filter drier should get me close to proper level of oil in the system.
Finally, if that does NOT work, then I must have gotten a bad rear expansion valve and its noisey, so I will have to then replace the rear expansion valve.