How to Install the DM1 Ultimate Shifter Kit Subaru STI (2015–2021) | Full Step-by-Step Guide

In today’s video, Erik from DARKMATTERX walks you through a full step-by-step installation of the DM1 Ultimate Shifter Kit on a 2019 Subaru STI. This guide covers everything you need to know for 2015–2021 STI models — and the install process is the same for 2008–2014 STI kits (only the shift boot differs). Whether you're upgrading for shorter throws, improved precision, or a cleaner driving feel, this video will serve as your complete install resource. Huge shoutout to Paradigm Automotive in Boise, Idaho for providing the shop space and support to make this install possible. They specialize in Subaru performance — from bolt-ons to full engine builds and tuning. ✅ What’s Covered in This Video: What comes in the DM1 Ultimate Shifter Kit Required tools for installation Interior disassembly Removing the factory shifter assembly Installing the DM1 shifter box & precision shift arm Reverse lockout bracket install Shift stop adjustment (CRITICAL STEP) Alcantara shift boot installation Proper shifter height adjustment If you have questions about installation, reach out to: 📧 [email protected] 💬 If this helped you, make sure to like, comment, and subscribe for more Subaru performance installs and upgrades. ⏱ Timestamps 00:33 – DM1 Kit Overview (Model Compatibility) 02:49 – Tools Required for Install 03:25 – Removing Center Console 05:57 – Removing Shift Knob & Interior Trim 06:48 – Final Interior Removal Before Going Under Car 07:53 – Pro Tip: Put Car in 6th Gear 08:13 – Under the Car: Remove O2 Sensor 08:47 – Removing Heat Shield 09:50 – Removing Factory Shifter Assembly 12:36 – Removing Roll Pin from OEM Shift Arm 14:30 – OEM Shifter Fully Removed 15:05 – Preparing the DM1 Shifter Box 16:43 – Installing Shifter Box Under Car 17:47 – Installing DM1 Shifter Assembly 18:29 – Installing Precision Shift Arm & Thrust Washers 21:47 – Installing Upper Mounting Hardware 23:42 – Securing Shifter Box from Underneath 24:47 – Installing Protective Rubber Boot 27:35 – Reinstalling Roll Pin 28:03 – Securing Hose Clamps 28:51 – Reinstall Access Panel 29:35 – Installing Reverse Lockout Bracket 31:59 – Reinstall Heat Shield & O2 Sensor 32:24 – Installing Final Hardware & Bushings 33:44 – Tightening Shift Arm Connection (Important Adjustment) 35:23 – Setting the First Gear Shift Stop 37:51 – Ensuring Proper First/Second Gear Wiggle 38:18 – Installing Premium Alcantara Shift Boot 39:21 – Adjusting Shifter Height 40:06 – Reassembling Interior