Use the Nomenclature to better ID your Eaton Fuller 15 Speed Transmission:

Example: RTO-14715

FR = Fuller Roadranger

R = Roadranger

T = Twin Countershaft

L = Low-Inertia Concept

O = Overdrive

X = Overdrive

First & Second Digits x 100 = Nominal Torque Capacity

Third Digit = Design Level

Fourth & Fifth Digits 15 = Forward Speeds