Loose drive wheel

I have the DaVinci 2.0 Duo and I was having a problem where my printer would print the calibration line at the start of each print but then would extrude nothing as it started to print the actual object. I thought it might be just the object I was slicing and that the first couple of layers were faulty so I tried printing one of the test pieces built into the printer firmware and got the same result. I tried unclogging both nozzles with the tools given. I finally opened up the extruder to clean out the drive gear and wheel and the silver wheel for the left extruder (extruder 2) is completely loose and does not contact the brass drive gear which causes the filament not to extrude in the left extruder. It's held on with a c-clip but I can't seem to tighten it or push it further back. I have not had the chance to test the right extruder again after cleaning it. Any suggestions?