Quick Answer

Choose a boot retainer with the same thread pitch and diameter as your shift knob and shifter—12x1.25mm for most Subaru and Toyota models, 10x1.25mm for Mazda, Mitsubishi, Nissan, and Infiniti. If you're unsure, check your knob's thread size or your vehicle's spec before ordering.

Why Thread Pitch Matters

The boot retainer threads onto the shift lever just below the knob, so it must match both the knob's internal thread and the shifter's thread. If the pitch or diameter is wrong, the retainer won't thread on securely, and you'll be back to the gap you were trying to eliminate.

Thread pitch is the distance between threads, usually expressed in millimeters (e.g., 1.25mm). Diameter and pitch together form the size, like 12x1.25mm. Getting both right is non-negotiable for a clean, rattle-free install.

Common Fitments and Exceptions

Most Subaru and Toyota applications use a 12x1.25mm thread, but there are exceptions—like the Toyota Tacoma (2005+) which uses a dedicated retainer. Mazda, Mitsubishi, Nissan, and Infiniti typically use 10x1.25mm.

If you have a Subaru 5-speed (WRX, Impreza, Forester), there's a specific retainer designed for that shifter. Always confirm your vehicle and transmission type before purchasing, especially if you've swapped in a short shifter or aftermarket shift lever.

How to Choose Your Boot Retainer

  • Check your shift knob thread pitch: Look at the knob's box, listing, or the thread itself. If it says 12x1.25mm or 10x1.25mm, that's your retainer size. If you have a Billetworkz knob, match it to the same thread size.
  • Confirm your vehicle and shifter type: Use a vehicle-specific retainer when available, like the Toyota Tacoma (2005+) option. For Subaru 5-speeds (WRX, Impreza, Forester), choose the Subaru 5-speed retainer. If you have an aftermarket short shifter, verify the thread size matches the original. If you have a short shifter, double-check that the thread size matches the retainer—some short shifters use the same threads, but it's worth confirming.
  • Match the retainer to your knob's thread: The retainer threads onto the shifter, and the knob threads on top of it. Therefore, the retainer and knob must share the same thread size. If you're using a 10x1.25mm knob, get a 10x1.25mm retainer.
  • Consider the finish and material: All Billetworkz retainers are machined from 6061 aluminum and hand-polished to a mirror finish. If you want a color match, check the available Boot Retainer Color options to complement your knob. Pick a color that matches your shift knob for a cohesive look.

Boot Retainer Options to Consider

Fitment Guidance

Best for

  • Subaru and Toyota owners with 12x1.25mm threads looking to close the gap between boot and knob
  • Mazda, Mitsubishi, Nissan, and Infiniti owners with 10x1.25mm threads who want a clean, factory-finished interior

Not for

  • Drivers with non-standard thread sizes (e.g., 12x1.5mm or 12x1.75mm) unless a compatible retainer is available
  • Vehicles with a shift boot that attaches directly to the knob without a retainer—this product won't help