Frequently Asked Questions About Semi-Truck Shifter Extensions Airline Kits

Will these shifter extensions fit my specific truck make and model?

Most shifter extensions and airline kits are designed as universal fitments that work with standard transmission shifter threads (typically 1/2"-13 or 3/8"-16). However, compatibility depends on your transmission type rather than truck make/model. Eaton Fuller 9, 10, 13, and 18-speed transmissions generally use the same thread patterns. Before ordering, check your current shifter knob thread size or consult your transmission manual. Some older models or specialty transmissions may require adapters.

What's the difference between aluminum and stainless steel extensions, and which should I choose?

Aluminum extensions are lighter (typically 30-40% less weight), more affordable, and available in various anodized colors but may show wear over time with heavy use. Stainless steel extensions offer superior durability, resist corrosion better, and maintain their appearance longer but add more weight to your shifter. For daily drivers who shift frequently, stainless steel is worth the investment. Weekend drivers or those wanting color options often prefer aluminum.

How difficult is installation, and what tools do I need?

Installation typically takes 10-15 minutes and requires minimal tools. You'll need: a wrench to remove your current shifter knob (usually 7/8" or 1"), thread locker (blue Loctite recommended), and possibly pliers for stubborn knobs. Simply unscrew your existing knob, thread the extension onto your shifter shaft, apply thread locker, tighten firmly, then install your knob on top of the extension. No drilling or modifications required for most applications.

What length extension should I get, and will it affect my shifting?

Extension lengths typically range from 2" to 12", with 4"-6" being most popular. The right length depends on your seating position and arm reach. Taller drivers or those with air-ride seats often prefer 6"-8" extensions. Longer extensions do increase leverage, making shifts feel slightly different - some drivers report smoother shifting, while others need a brief adjustment period. Start with a moderate length (4"-6") if unsure.

Can I use my existing shifter knob with these extensions, or do I need a new one?

Yes, most existing shifter knobs will work with universal extensions as long as the thread patterns match. Extensions typically have male threads on bottom and female threads on top that match standard shifter specifications. However, this is an excellent opportunity to upgrade to a weighted or ergonomic knob if desired. Just ensure any new knob matches the thread size of your extension's top threads (usually the same as your transmission's original specs).