You might have bought a vehicle with a bad PTU but I am skeptical as I have worked on several of these units and mine had 210miles on it when I bought it never had the fluids changed in the PTU and I chanced the fluid and never had an issue with any of them and I have worked on several with over 200,000 miles had all kinds of issues from poor maintenance but no PTU issues ever. I suspect that his is an internal transmission issue if not I would get someone to replace the PTU this would at the very least eliminate this as a cause. PTU if it were me I would try and source a good used one from a recycler as I said never had any issues with them. This would keep the costs down and confirm issue being PTU or transmission. The PTU is not easy to replace though either as it does not look like you can remove it without removing the transmission. You might be able to just seemed very tight when I have been doing transmission Re and Re jobs.UPDATE: I got the Mopar part number for the driver's side CV axle and crossed it over to a GSP number (GSP is the aftermarket axle manufacturer). I brought the Patriot in to the shop yesterday and the part they installed has the correct number. They replaced the driver's side axle under warranty but it still shakes where the inner axle goes into the transfer case. They ran the Jeep on a lift and the shake is obvious. I also noticed a slight shake in the passenger's side axle, but it's nowhere near as pronounced as the driver's side.
I assume there is a bearing in the transfer case that has gone bad. Can anyone name that part so I know what I'm asking about? Can the bearing be replaced without dropping the transfer case and/or transmission? Any idea of cost/labor time involved? Would a drive-line shop be a good choice to try? I live in Freehold, New Jersey 07728 (Jersey Shore area) if anyone has a recommendation.
Sorry for the long post. I appreciate everyone's help.