What is the thread pitch of the shifter on a Subaru STi?
The shifter knob on most Subaru STI models threads onto the shift lever using a standard metric size: M12 with a 1.25 mm pitch. This is the most common configuration, though some years or aftermarket parts may differ. Confirm your exact car and knob before purchasing or replacing.
Understanding what thread pitch means for a shifter knob
Thread pitch describes how fine the screw threads are and how many threads the knob will engage as you tighten it. Getting the pitch right is essential for a secure fit that won’t loosen under spirited driving, and it helps prevent cross-threading or wobble.
The most common sizes you may encounter
Before listing sizes, note that STI shifters most often use M12x1.25. Some aftermarket knobs or adapters may offer compatible alternatives or require adapters to fit different thread pitches. The guide below reflects what buyers typically see.
- M12x1.25 — the standard size for many STI shifter knobs and common aftermarket replacements
- Other possibilities (less common) include M10x1.5 or M14x1.5 for certain aftermarket knobs or adapters
- Some universal knobs ship with multiple adapters to cover a range of thread sizes
Conclusion: The majority of STI shifter knob installations use M12x1.25, but always verify the exact specification for your generation and any knob/adaptor you plan to install.
How to verify the pitch on your specific vehicle
To avoid buying the wrong knob or adapter, verify the thread pitch on your car before purchase. Use the steps below to confirm the size on your shift lever.
- Remove the stock shift knob following the owner's manual or service procedure for your model and year
- Inspect the lever stud: measure its diameter with calipers and look for a visible thread pattern
- Use a thread pitch gauge or a metric ruler to determine the pitch (in millimeters per turn) and the diameter
- Cross-check your measurements with product specs or ask the seller for the exact thread pitch before buying
Conclusion: Accurate measurement prevents cross-threading, wobble, or knob failure while driving.
Summary
For Subaru STI shifter knobs, the prevailing standard is M12x1.25. Confirm the exact pitch for your generation and any aftermarket parts before purchasing. When in doubt, consult a Subaru technician or reference your vehicle’s service manual.
