Lisle 22100 Flywheel Locking Tool for 6.6L Duramax with Allison Transmissions

Overview

The Lisle 22100 Flywheel Locking Tool is purpose-built for 6.6L Duramax engines paired with Allison automatic transmissions. It helps technicians keep the flywheel securely stationary during harmonic balancer work, reducing the chance of slips or misalignment while the balancer is removed.

Why it matters in the shop

Duramax service often involves steps where the flywheel must stay fixed. This tool provides a reliable engagement point at the transmission side, enabling you to handle the balancer or water pump tasks with more control. By limiting the need to pull extra components, technicians can maintain a smoother workflow and stay focused on the task at hand.

• Locks the flywheel in place when removing the harmonic balancer on 6.6L Duramax engines with Allison automatics.
• Saves time by locking the flywheel at the transmission instead of removing the starter for water pump replacement.
• Operates with a 36mm 12-point socket and 3/4" square drive to remove the balancer bolt and re-torque on installation.
• Compact packaging helps keep your toolbox organized (approx. 4.5" W x 5" H x 2" D).

How to use

The tool is designed for straightforward integration into standard Duramax service steps. It slides into the appropriate opening at the bottom of the transmission and engages the flywheel teeth, then is secured by hand. When finished, recheck torque with a 36mm socket as you reinstall the harmonic balancer.

• 2500/3500 pickups: access through the bottom metal inspection plate; slide the tool toward the engine to engage the flywheel teeth.
• 4500/5500 trucks: access through the bottom rubber inspection cap; insert from the front to engage and hold the flywheel.
• Use a 36mm 12-point socket with a 3/4" square drive to remove and re-torque the balancer bolt during installation.

With its compact profile and precise fit for Duramax flywheel teeth, this tool supports a steady, predictable engagement during a balance- or timing-focused service. It’s a practical addition for technicians seeking clearer workflow and consistent results without unnecessary disassembly.