The Eaton Fuller 4300318 is an auxiliary mainshaft reduction gear used in RTX and RTXF series heavy-duty transmissions. Per the Eaton illustrated parts list, it is identified as a reduction gear (superseding part number 20475) within the Mainshaft and Synchro (Aux) group. Confirmed fitment covers the Fuller 12609, 12610, and 13609 series, with specific manual coverage for the RTX-12609A, RTX-12610, RTX-13609A, RTXF-12609A, RTXF-12610, and RTXF-13609A models. Call us to confirm proper fit for your specific transmission.
Interchanges:
- 900690
- FULLER 20475
- GMC TRUCK 15515746
- MACK 2719-20475
- MACK 2719-4300318
- MACK 3088-20475
- MACK 3088-4300318
- MACK 4333-1685864C1
- NAVISTAR 1685864
- NAVISTAR 1685864C1
- VOLVO 3134335
Features
Auxiliary mainshaft reduction gear for Eaton Fuller RTX and RTXF series transmissions
Direct fitment for Fuller 12609 Series, 12610 Series, and 13609 Series
Listed in OEM illustrated parts manuals for RTX-12609A, RTX-12610, RTX-13609A, RTXF-12609A, RTXF-12610, and RTXF-13609A
Supersedes Eaton Fuller part number 20475
Sold individually as one gear per unit
