ATS 309-812-4290 Stage 1 Allison LCT1000 Crate Transmission | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY 2WD

Features:

• Includes ATS Stage 1 performance transmission
• Built for 2004.5–2005 Duramax LLY 2WD trucks
• Comes with ATS Five Star torque converter
• Includes ATS deep transmission pan
• Improves reliability for towing and daily driving
• Supports stock to mild performance upgrades
• Upgraded internals handle increased torque loads
• Reduces heat with expanded fluid capacity
• Delivers smoother and more responsive shifting
• Ideal for work trucks and heavy-use applications
• Built and tested in the USA by ATS Diesel
• Professional installation is strongly recommended

Keep Your LLY Moving Stronger Longer With The Right Upgrade

If your Duramax LLY is still putting in the work but you feel the factory transmission starting to lag behind, it is time to step things up. The ATS Stage 1 Allison LCT1000 Crate Transmission is built for truck owners who rely on their Silverado or Sierra every day and do not want to worry about weak shifts or transmission failures when it matters most. Whether you are towing equipment, hauling heavy loads, or just racking up serious mileage, this upgrade gives your truck the durability and smoother performance it deserves. ATS includes their proven Five Star torque converter to get better torque multiplication and reduce wasted power at the wheels. Plus, the deep transmission pan helps keep operating temperatures under control when the workload gets heavy. It is a package designed to improve real-world performance without sacrificing comfort or driveability. If you want your LLY to keep working hard for years to come, this transmission gives you the strength to back it up.

A Smarter Transmission Package For Towing And Everyday Durability

The ATS 309-812-4290 Stage 1 Transmission package is engineered to meet the needs of 2004.5–2005 GM 2500HD and 3500HD trucks equipped with the 6.6L Duramax LLY engine and two-wheel drive. This package features an upgraded Allison LCT1000 transmission that uses strengthened internals and optimized shift strategies to support increased torque from towing, hauling, or mild tuning. It also includes the ATS Five Star torque converter, which is designed to reduce slippage and provide more efficient power delivery during heavy load conditions. To help manage heat and extend transmission life, the ATS deep transmission pan increases fluid capacity and improves cooling performance. This combination is ideal for truck owners who need better reliability and consistent performance without going overboard into race-spec components. Every transmission is assembled and tested in the USA by ATS Diesel to ensure maximum quality and lasting dependability. It is a complete upgrade designed to keep your truck moving strong under real working conditions.

Fits: 2004, 2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY 2WD

Notes:

• Designed specifically for 2004.5–2005 GM 2500HD and 3500HD trucks with 6.6L Duramax LLY engines and 2WD.
• Includes ATS Stage 1 transmission, Five Star torque converter, and deep transmission pan.
• Recommended for trucks with stock to mildly modified engines used in towing or daily driving.
• Not designed for high-performance or competition use.
• Torque converter improves low-end torque delivery and reduces slippage under load.
• Deep pan increases fluid capacity for better cooling under stress.
• Transmission may produce firmer shifts compared to the factory unit.
• Professional installation is strongly recommended to ensure proper function and warranty compliance.
• All components are built and tested in the USA by ATS Diesel for quality assurance.
• A $500 shipping surcharge will be added at checkout and is not included in the listed product price.