[Technick]

Now that I think about it........................... If you have a aftermarket shifter with the adjustable stops so that you do not overthrow the shifter.......... like a Steeda, B&M, Pro-5.0, ect. you may have had the bolt for the stop in 2nd, 4th, and rev. come loose and vibrate forward and that is keeping the shift handle from comming back far enough to allow a gear change! I had this happen to me once during a dyno session. Was really thrown by if for about 5 min. and then I looked under the shift boot and sure enough that bolt had come loose. A simple adjustment and all of the gears came back........ no damage done except to my ego for a few moments. Never hurts to take a look.