I don't mean to hijack your 4th gen thread, but I had the same problem with my 3rd gen 08. 36,508 miles and it ended up being the steering gear... of course I didn't know that until the gear completely froze up, luckily I was stopped in a parking lot.
The gear had seeped (ever so slightly) fluid from where the two sections of it bolt together. I don't know if the gear uses power steering fluid to lubricate or if it has separate gear lube internally, but once the gear was off, it was obvious it was leaking. I also experienced brake issues in the parking lot just before it froze up.
Short version of a long story; I'm from KC,MO. broke down west of CO. Springs. Truck towed to CO. Springs Dealer, I was informed the part was on back order and it would be at least 7 days before it came in. That wasn't gonna work, had them put a NAPA gear on and a new Dodge pump and cooler to get me home (Pump, cooler and labor under warranty, NAPA gear and labor on me). The NAPA gear was too tight and did not return the truck to center steer and it had 1/2 inch of free travel on either side of center. Once home, had my dealer order a new dodge gear... 34 days before it came in. Dealer put the gear on and now they are in process of getting me my money back for the NAPA gear and labor.