The M113 is a tracked vehicle used by the united states millitary. It reqires a lot of maintenace. There are a lot of diffrent steps to maintaining a M113. The dirtiest job that I know of is pulling the power pack. The power pack is the engine and transmission of the vehicle. Before you pull the power pack you have to drain the engine and transmission of oil, about thirty gallons of really dirty oil in all. When the power pack is removed you have to clean out the hull where all the leaked oil has collected over time. Lots of little nooks and crannies for oil, dust, dirt, grime and gunk to build up in. It would be cool if mike did this.