About half way through my ride yesterday I started having a really hard time turning. It wanted to track in a straight line. My arms are damn tired. It almost felt like driving with the locker on, but it wasn't and it wasn't froze either. Any ideas as to what's causing this?

 

mayb your front differential got stuck in the locked position halfway between transferring the torque between the two fronts even though your lock lever wasnt engaged. next time it does that, jack up your quad so all the wheels are off the ground, and give it slight throttle in 4x4 to see if both fronts are turning, if they are and the levers not engaged, then its the diff.