E-cowlboy Flywheel Locking Tool for 6.6L Duramax with 36mm 3/4" Socket — CRV Steel, High-Torque

The E-cowlboy Flywheel Locking Tool secures the flywheel so you can safely remove and reinstall the harmonic balancer on 6.6L Duramax engines with Allison automatic transmissions.

If you work on Duramax 6.6L engines, this purpose-built locking tool speeds service by holding the crankshaft steady without removing the starter. Forged from CR-V steel and supplied with a 36mm 12-point socket for a 3/4" drive, the set resists corrosion and stands up to high torque jobs like crank pulley removal and re-torqueing.

How does this tool fit different Duramax models?

Installation depends on the model year and transmission access. For 2500/3500 pickups the tool uses the toothed pieces only and drops in under the transmission’s spring-loaded inspection plate; for 4500/5500 trucks the included toothed pieces with screws are used after removing the rubber inspection cap. In both cases the top of the tool engages the flywheel teeth to lock rotation.

• 2500/3500: remove metal spring-loaded inspection plate and slide tool toward engine.
• 4500/5500: remove rubber cap, insert tool at front, hand-tighten securing bolt.
• Top of tool meshes with flywheel teeth to prevent crank rotation.
• Designed specifically for Allison automatic transmissions in 6.6L Duramax engines.

What are the materials and torque capabilities?

The main body is made from chrome-vanadium (CRV) steel, a durable alloy chosen for strength and corrosion resistance. The supplied forged 36mm 12-point socket fits a 3/4" square drive and is built to withstand the high torque needed to remove the harmonic balancer bolt and re-torque it on installation.

• CRV steel construction for long-term, rust-resistant service.
• Forged 36mm 12-point socket for durability under heavy torque.
• Socket also compatible with axle work when a 36mm fit is required.
• Engineered to handle crank pulley torque values common on Duramax engines.

How simple is it to use during routine service?

The tool is designed for straightforward use through the transmission inspection opening, so you typically do not need to remove the starter. It slips into place and either engages the flywheel teeth or secures with the supplied screw depending on truck model, making crank pulley removal and installation faster and cleaner.

• Slides into inspection opening—no major disassembly required on most trucks.
• Hand-tightened screw holds tool in place on 4500/5500 models.
• Makes loosening and tightening the harmonic balancer bolt more controllable.
• Saves time on jobs like water pump or front-end service compared with full starter removal.

Who is this for: Professional mechanics, independent diesel specialists, and experienced owners who work on 6.6L Duramax trucks with Allison automatic transmissions will benefit most from the E-cowlboy Flywheel Locking Tool. It’s especially useful for technicians who perform harmonic balancer, crank pulley, or front-end service and need a reliable method to hold the crankshaft steady without extra teardown. The rugged CRV construction and 36mm forged socket make it a practical addition to a diesel toolset for repeat use in heavy-duty service environments.