New parts for the shifter mechanism assembly rebuild came from the "overnight(s) shipping". I will edit images and post of the worn shift arm, shift lever comp. and interlock so you can see potentially what these look like from grinding gears and not shifting correctly. The previous owner was responsible, I have 30 years experience with manuals including commercial dump trucks. Potentially your shift arm and interlock may look like mine. Speedfactory has created a stronger version of the shift arm because of the way they wear and sometimes fail. The interlock bearing works against the gears of the shift arm by design. The interlock shaft bearing will become compressed and will destroy the shift arm teeth.