I have an 09 F250 Lariat package 4X4 (non FX4 package). I was wondering if these trucks came with an actual electric locker in rear or if it's just a limited slip rear differential. Reason why I'm asking is I was testing my front hubs b/c the front was not locking and the rear axle seamed to be fully locked in four wheel drive mode even when the front was not engaged due to the hubs not locking. When I would turn the tires felt like they were grabbing and left tire tread on the driveway. Anyway seamed different.