I recently bought a 2001 Silverado 2500HD, auto trans, with the manual shift transfer case. Here's the problem..., the front end does not lock in (front wheels receive no power) when shifting into either 4 hi or 4lo. I dropped the skidplate and pulled the four wheel drive actuator out of the housing and it appears to be working. (It extends about an inch or so when the t-case is placed into four wheel drive.) The 4wd indicator on the dash lights up and the actuator looks to be working??? What am I missing?? I spend most of my time on solid axles on Jeeps, and I haven't a clue how the IFS shift on the fly works..., I'm used to the vac operated CAD systems. Any help would be greatly appreciated. Thx.