Last years Spring Clean Up Run I was on the Devil's Canyon side. We were on the back loop when suddenly there was a bang underneath the Bronco that I felt through the floorboards. All forward motion stopped, engine reved up and I started to roll backwards. Moving the gear shift did nothing. I was dead in the middle of the trail. I set the parking break, got out and looked everywhere under the Bronco. No fluid leaking out, nothing hanging down. A few others came and joined in on the investigation and none of us found anything. I got back in the Bronco (it was still running) and my knee bumped the 2wd/4wd selector. I heard the gears grinding. We discovered my knee had hit the shifter on a bump and knocked the T-case into neutral. I felt like such an idiot.