SKU: ATS309-864-4290

Stage 6 Allison LCT1000 Crate Transmission

Ships From Manufacturer in 15-20 Days
Confirmed fitment below
YEARS
2004.5-2005
MAKE / MODEL
GM/Chevrolet/GMC / Silverado/Sierra
SERIES
2500HD/3500HD
ENGINE
6.6L Duramax LB7/6.6L Duramax LLY
Price
$11,284.99
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PRODUCT DETAIL

Key Features & Description

Features:

  • Fits 2004.5–2005 LLY Duramax 4WD trucks
  • Includes ATS Stage 6 performance transmission
  • Comes with Five Star torque converter
  • Deep transmission pan increases cooling capacity
  • Includes ATS Co-Pilot transmission controller
  • Billet input, output, and intermediate shafts
  • Billet P2 carrier and C2 hub for added strength
  • Ideal for high horsepower and towing applications
  • Improves torque handling and shift precision
  • Replaces weak factory components with billet upgrades
  • Complete crate unit ready for direct installation
  • $500 shipping surcharge applies

When Your LLY Is Built For More This Is The Transmission That Keeps Up

If you're putting serious power into your 2004.5–2005 LLY Duramax, your transmission better be ready to handle the heat. The ATS Stage 6 Allison LCT1000 Crate Transmission is designed for truck owners who expect performance, durability, and reliability with every shift. Whether you’re towing a heavy trailer, climbing steep grades, or pushing big horsepower numbers on the street or strip, this package gives you the tools to stay in control. It comes fully loaded with billet internals, a high-efficiency Five Star torque converter, a deep transmission pan for cooling, and the Co-Pilot transmission controller to manage shifting in real time. It’s a complete, ready-to-install solution that eliminates the weak points of the stock transmission so you can get the most out of your build. You’re not just replacing a transmission, you’re upgrading your truck’s entire driving experience. If you want your LLY to run hard and shift smooth no matter what you throw at it, this is the setup to trust.

Precision Engineering Designed To Survive High Torque Builds

The ATS 309-864-4290 Stage 6 Allison LCT1000 Crate Transmission is a purpose-built performance unit made for the demands of 2004.5–2005 6.6L Duramax LLY 4WD applications. It features billet input, output, and intermediate shafts that resist twisting under heavy torque, along with a billet P2 carrier and C2 hub to increase the strength of internal rotating assemblies. A modified P1 sun gear is also included to further reinforce the drivetrain for aggressive use. The package is completed with the ATS Five Star Torque Converter, which enhances torque multiplication and lock-up control for improved responsiveness and towing confidence. A deep transmission pan increases fluid capacity and helps regulate temperatures during sustained heavy loads or high-RPM performance driving. With the included ATS Co-Pilot Transmission Controller, this setup dynamically adjusts shift pressure and timing based on real-time driving inputs. It’s engineered as a complete crate solution to eliminate guesswork during installation and maximize drivetrain reliability. A $500 shipping surcharge applies due to the size and weight of the full system.

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

Notes:

  • Designed for 2004.5–2005 6.6L Duramax LLY 4WD trucks.
  • Includes ATS Five Star Torque Converter and Co-Pilot Controller.
  • Ships as a complete crate transmission, ready to install.
  • Billet input, output, and intermediate shafts increase strength.
  • Billet P2 carrier and C2 hub improve internal durability.
  • Modified P1 sun gear helps handle extreme torque levels.
  • Deep transmission pan included for added cooling and fluid volume.
  • Ideal for high horsepower builds and heavy towing applications.
  • Co-Pilot controller manages shift timing and pressure automatically.
  • $500 shipping surcharge will be added due to size and weight.

FITMENT GUIDE

Exact Fitment — Verify Your Year

Year RangesYears
Make
Model
Series
Engine
2004.5-2005
GM/Chevrolet/GMC
Silverado/Sierra
2500HD/3500HD
6.6L Duramax LB7/6.6L Duramax LLY

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