I'm new to posting in forums like this although I've used them to solve vehicle issues in the past -- and very thankful for these forums because of that! Anyways, just got a 2005 Chevy Silverado 1500 5.3L 4x2 (176K miles) and everything looks beautiful - under-the-hood is cleanest I've ever seen! However, the problem is that when driving the truck, it wont shift out of first gear. The speedometer & tachometer work fine (it will rev up to 6000rpms but still wont kick into a higher gear). It doesnt clunk or slip or make any weird noises or anything, just will not get out of first gear. Checked some online threads and saw a lot of people with similar issues getting suggestions to check the neutral safety switch and the vehicle/transmission speed sensor, so we went and bought those, replaced them in the truck, but the problem still persists. (Also saw a lot of threads where people got new or rebuilt trannys and still had the problem, so we don't want to jump to that until we know its necessary.) Also worth mentioning, no codes came up when plugged into a scanner... Can anyone help with this issue? Is there another sensor we should check out? Does anyone have ANY suggestions to help us troubleshoot this problem? Why wont it get out of first gear!? Please help!