about the motor mount idea . . . . .
it only happened a few times, but my 4LO popped out occasionally.
i replaced the motor mounts (because they were worn out, not because the 4LO coming out) just before my trip to Moab a few weeks back.
now that im thinking about it, my 4LO never came out and gave me an issue.
if you do decide to replace your motor mounts,
may i suggest Brown Dog Offroad
, these guys rock!