109-7431 hex-pilot shaft for a mower deck spindle
This replacement is the shaft inside a matching deck spindle assembly. It has a hex pilot and circular shoulder at one end, a smooth shaft body, and an external threaded section at the other. One black steel shaft is supplied. The spindle housing, bearings, spacer, pulley and blade hardware are separate parts.
Check the deck's parts diagram
The listed applications are Exmark Quest, Pioneer E-Series, Radius E-Series and Radius S-Series. Match reference 109-7431 in the parts diagram for your exact mower model, serial number and deck configuration before ordering. The series name alone does not establish compatibility with every deck.
Compare the removed shaft's overall length, bearing-contact surfaces, shoulder, hex pilot and threaded end. The shaft needs to match the surrounding housing, bearings and blade connection; a similar-looking complete spindle assembly may use different internal parts.
Shaft details
- Replacement reference
- 109-7431
- Quantity
- 1 spindle shaft
- Material and appearance
- Steel, black
- Overall length shown
- 6.3 inches, from the hex-pilot end to the threaded-end face
- Shaft body diameter shown
- 0.66 inch
- End features
- Hex pilot with a central opening; external threads at the opposite end
The pictured dimensions are comparison measurements. They do not specify the hex size, thread diameter or pitch, bearing fit or machining tolerances. Check those interfaces against the original shaft if its identity is uncertain.
Inspect the rest of the spindle
Inspect the bearings, housing seats and spacer when the assembly is apart. Replacing the shaft will not correct wear in those separate components. Follow the service procedure for the exact deck when rebuilding the spindle and securing the pulley and blade. Use that procedure's fastener settings rather than treating a diagram's torque labels as instructions for every listed mower.
