Shop 671 gearbox main shaft gear from 6 trusted brands including EURORICAMBI, CEI, NTY. Compare prices, check vehicle compatibility, and get free delivery on orders over £50.
The main shaft (or output shaft) of a manual gearbox carries the gears that transmit drive from the layshaft to the output flange. Gear teeth wear, splines degrade, and bearing journals become worn over high mileage, particularly in vehicles subjected to hard acceleration and towing. Main shaft replacement is a significant gearbox overhaul task, usually undertaken when a gearbox is stripped for bearing or synchro ring replacement.
Main shaft issues are rarely the first failure in a gearbox — they usually develop alongside synchro hub and bearing wear.
Main shaft replacement requires full gearbox disassembly. It should be treated as an opportunity to inspect and replace all worn internal components.




Commonly searched OE numbers fitting Gearbox Main Shaft Gear from the TecDoc catalogue.