ATS 309-824-4290 Stage 2 Allison LCT1000 Crate Transmission | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY 4WD

Features:

• Fits 2004.5–2005 Silverado and Sierra HD 4WD
• Designed for 6.6L Duramax LLY engine applications
• Includes ATS Stage 2 Allison LCT1000 transmission
• Comes with ATS Five Star torque converter
• Features ATS deep pan for extra cooling capacity
• Includes ATS Co-Pilot transmission controller
• No tuning or reprogramming required to install
• Built to handle towing and added horsepower
• Improves shift quality and torque management
• Fully assembled crate transmission ready to install
• Ideal for heavy-duty and performance driving
• $500 shipping surcharge applied at checkout

Get Your LLY Back To Pulling Strong And Shifting Smart

If your 2004.5 to 2005 Duramax has started showing signs of a tired transmission, it might be time to upgrade to something built for more than just factory expectations. The ATS Stage 2 Allison LCT1000 Crate Transmission Package is designed to bring real performance, reliability, and peace of mind back to your Silverado or Sierra 2500HD or 3500HD 4WD. This isn’t a basic rebuild, it’s a full transmission system built to hold up under towing stress, throttle-heavy driving, and the demands of a modern diesel owner. You get the performance-built Allison LCT1000, ATS’s Five Star torque converter for better power transfer, and a deep transmission pan that keeps temps under control when the work gets heavy. The Co-Pilot transmission controller gives your truck smarter shifting and more responsive control without needing tuning or reprogramming. Whether you’re hauling up a grade or cruising through town, you’ll feel the confidence in every shift. It’s a premium transmission package made for trucks that still have work to do.

Built To Withstand Load Heat And Daily Demands

The ATS 309-824-4290 Stage 2 Crate Transmission is a complete upgrade solution for 2004.5 to 2005 GM 2500HD and 3500HD trucks running the 6.6L Duramax LLY engine and 4WD setup. At the heart of this system is a fully built Allison LCT1000 transmission featuring upgraded internals designed to handle elevated torque and frequent towing loads. The package includes the ATS Five Star torque converter, which improves torque multiplication, reduces slippage, and enhances overall drivability under stress. Also included is the ATS deep transmission pan, which increases fluid capacity and promotes better cooling, especially useful for long hauls and stop-and-go operation. The Co-Pilot transmission controller ensures stable line pressure, better shift timing, and more precise torque converter management, all without requiring custom programming. It’s designed to plug right in and work seamlessly with your truck’s existing systems. Whether you're pushing your truck to its limits or just want a reliable upgrade for daily performance, this package brings lasting durability and smoother control to every mile.

Fits: 2004.5, 2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY 4WD

Notes:

• Fits 2004.5–2005 Silverado and Sierra 2500HD/3500HD 4WD models
• Designed specifically for the 6.6L Duramax LLY engine
• Includes ATS Stage 2 Allison LCT1000 transmission
• Package comes with ATS Five Star torque converter
• Deep transmission pan improves cooling and fluid capacity
• ATS Co-Pilot controller enhances shift control and performance
• No custom tuning or programming required for operation
• Ideal for towing, performance upgrades, and heavy daily use
• Transmission ships fully assembled and ready for installation
• Professional installation is strongly recommended
• $500 shipping surcharge will be applied at checkout