8330-3121 Coleman-Mach

8330-3121 Coleman-Mach AC Selector Shaft Extender

  • $ 11.83
    Unit price per 
  • Save $ 3.16
Shipping calculated at checkout.


8330-3121 Coleman-Mach AC Selector Shaft Extender

Restore smooth, wobbly-free knob operation in your Coleman-Mach RV air conditioner control assemblies with this genuine OEM selector shaft extender. Designed to slip over the original steel temperature-selector shaft, it provides the precise length and fit needed for accurate thermostat adjustments.


📋 Compatibility & Fit

  • OEM replacement for part numbers 8330-312 and 8330-3121

  • Works with Coleman-Mach Mach 3 (38203-066/069), Mach 3 Plus, Mach 8 and 9-Series control boxes

  • Compatible with thermostats such as 8330-3362 (analog zone control) and 8330A3341 (5-button Zone Control)

⚙️ Technical Specifications

Specification Details
Material Black-anodized aluminum
Inner Diameter 1/4 inch (fits 0.250″ selector shaft)
Outer Diameter 3/8 inch (0.375″)
Length 1.75 inches
Included Hardware (2) Stainless set screws, nylon washer

🔧 Customer Benefits

  • Ensures firm engagement between the shaft and thermostat knob for precise temperature control

  • Genuine OEM fit prevents slippage and reduces service callbacks

  • Simple slip-over installation—no modifications, drilling, or adhesives required