Fuller RT-910/RT-915 to RTO-910/RTO-915 Overdrive Conversion Procedure

This document is a service procedure page explaining how to convert a Fuller/Roadranger RT-910 or RT-915 direct-drive transmission into its overdrive counterpart, the RTO-910 or RTO-915. The conversion is accomplished by interchanging two sets of gears (three gears in each set): the fourth speed gear on the mainshaft and its two mating countershaft gears are swapped with the main drive gear and its mating countershaft drive gears. The procedure notes that the transmission front section must be completely disassembled because the drive gear on each countershaft must be removed. A bolded warning instructs the technician to ensure gear hubs are in the correct position during reassembly, as described in the manual's detailed reassembly section. No extra parts other than gaskets are required, although a new drive gear bearing nut may be needed since this part can be damaged during removal. The page includes a labeled cross-sectional illustration of the front section of the RT-910 and RT-915 transmission, with arrows identifying the two gear sets to be interchanged: the drive gear set and the 4th speed gear set. A reader learns the scope, parts requirements, and key cautions for performing this RT-to-RTO overdrive conversion.