The main countershaft cleaned and being prepped for reinstallation. The gear cluster is a one piece unit that rides on roller bearings on each end of the cluster. These bearings need to be put in, then the cluster placed into the bottom of the case, but the countershaft itself cannot be put in until the input shaft has been installed (again for clearance for the 4th gear teeth). Hence a "dummy shaft" that will retain the bearings, but is shorter than the real countershaft needs to be used. Following a "trick" provided by the instructions in the rebuild kit, a 7/8 inch wooden dowel, cut to length, is just the ticket.