My daughter bought a 2006 2wd a couple of months ago The trans was replaced (assuming rebuilt swap) 9 months ago by a Chevy dealer, 500 miles away from me. It has a thump in the 2-3 shift, seems to take more pedal to get that shift than it should. 1-2 shift is normal. A few days ago, it started slipping out of 2nd gear in 30 mph city driving when coasting. Excessive throttle needed to get it to go back in gear (bigger thump). Under moderate highway driving acceleration, it stays in gear and shifts okay (except for the 2-3 thump). Any feedback would be appreciated.