Stage 3 Allison LCT1000 Crate Transmission

Features:

• Fits 2004.5–2005 GM 2500HD/3500HD 2WD
• Designed for 6.6L Duramax LLY engines
• Includes ATS Stage 3 LCT1000 transmission
• Comes with Five Star torque converter
• Billet input shaft for added strength
• Includes deep transmission pan
• ATS Co-Pilot transmission controller included
• Built for high power and heavy towing
• Improves shift quality and transmission life
• Complete crate transmission upgrade package

Serious Transmission for Serious Power and Towing

If you’re running a 2004.5–2005 GM 2500HD or 3500HD with a 6.6L LLY Duramax and plan on pushing the limits—whether that’s with towing, performance upgrades, or both—the ATS Stage 3 Allison LCT1000 Crate Transmission is built for your kind of driving. This isn’t a patched-up rebuild or lightly modified unit—it’s a full crate transmission designed from the ground up to handle the abuse that comes with added power, aggressive tuning, and hauling serious weight. At the heart of the package is a fully upgraded LCT1000 transmission, paired with ATS’s proven Five Star torque converter. That means smoother lockup, improved efficiency, and better throttle response under load. You also get a deep transmission pan to increase fluid capacity and cooling, which becomes critical when pulling heavy or running in high-heat conditions.

Reinforced Internals and Smarter Control

What sets this transmission apart is the attention to the internals and how it all works together under stress. The billet input shaft is designed to withstand high torque spikes that would twist or snap a stock shaft in performance applications. Pair that with ATS’s Co-Pilot transmission controller, and you’ve got smarter shift strategies that adapt to throttle input, load, and driving conditions, keeping shifts crisp and gear holding tight even when under pressure. It’s ideal for truck owners looking to eliminate factory transmission weaknesses without giving up daily drivability. Whether you’re building for performance, towing massive loads, or just want peace of mind behind the wheel, this Stage 3 setup delivers power-handling confidence with the kind of engineering that holds up mile after mile.

Fits: 2004.5, 2005 GM 2500HD/3500HD 6.6L Duramax LLY 2WD

Includes:

• ATS 2WD 2004.5-2005 Allison LCT1000 Performance Transmission
• ATS Allison LCT1000 Five Star Torque Converter (302-950-4248)
• ATS Allison LCT1000 Deep Transmission Pan (301-900-4248)
• ATS Co-Pilot Transmission Controller (601-924-4248)
• Billet Input Shaft

Note: $500 Shipping surcharge will be added at checkout