I had a repairman fix the fan on my refrigerator and he removed the right gear for the Rack Shaft saying it was broken and never came back to replace it. I called the shop and they said he was no longer with them and would not replace the gear and had no record that he took it. I bought the gears to replace it and cannot figure out how to reinstall them. The owners manual does not address the Rack Shaft so it is no help. Can anyone assist me?