I have a 1996 Suburban diesel that will not start. When I turn the key to the run position, all is well, when I turn the key to the start position, nothing happens. I have done a bunch of troubleshooting, and have narrowed down the problem to the gear mechanism between the cylinder and keys and the ignition switch. If I remove the ignition switch from the steering column, and turn the ignition switch with a flat blade screw driver, it goes to the run position, then the start position, and the engine starts normally. When I turn the key in the cylinder, the gear that operates the ignition switch turns, and does not seem to have a problem. When I put the ignition switch into the gear mechanism, and turn the key, the engine will not start. Has any one seen this problem and have a fix for it? What is the gear mechanism that connects the ignition switch to the cylinder and keys called? I can not find the part name on any parts list.