Product Description
The ATS 309-812-4290 Stage 1 Allison LCT1000 Transmission Package is a performance-enhanced replacement designed for 2004.5–2005 6.6L LLY Duramax trucks. Built to address factory transmission weaknesses, this 2WD package delivers improved reliability, smoother shifts, and increased holding power over stock.
This Stage 1 transmission is ideal for daily drivers, light towing, and mildly tuned trucks. ATS upgrades key internal components and clutch capacity to provide better durability while maintaining near-stock drivability. Paired with the ATS Five Star torque converter, this package improves power transfer and reduces slip under load.
If you're looking for a dependable upgrade without going extreme, the ATS Stage 1 transmission offers the perfect balance of performance and longevity for your Duramax.
FAQ
Q: What is the difference between Stage 1 and higher ATS stages?
A: Stage 1 is designed for stock to mildly tuned trucks, focusing on reliability and improved clutch capacity, while higher stages include billet shafts and are built for extreme horsepower.
Q: Is this transmission good for towing?
A: Yes, it is well-suited for daily driving and light to moderate towing with improved durability over the factory transmission.
Q: Does this package include a torque converter?
A: Yes, it includes the ATS Five Star torque converter to improve efficiency and reduce slippage.
Q: What power levels can this transmission handle?
A: This Stage 1 package is ideal for stock to mildly modified trucks, typically supporting moderate horsepower increases over stock.
Fitment
- 2004.5 Chevrolet Silverado 2500HD/3500HD 6.6L LLY Duramax (2WD)
- 2005 Chevrolet Silverado 2500HD/3500HD 6.6L LLY Duramax (2WD)
- 2004.5 GMC Sierra 2500HD/3500HD 6.6L LLY Duramax (2WD)
- 2005 GMC Sierra 2500HD/3500HD 6.6L LLY Duramax (2WD)
Key Features
- Improved clutch capacity over stock
- Enhanced durability for daily driving and towing
- ATS Five Star torque converter included
- Smoother, more consistent shifting
- Designed for stock to mildly modified trucks
- Direct replacement Allison LCT1000 transmission
Specifications for ATS 309-812-4290
| Specification | Details |
|---|---|
| Part Number | 309-812-4290 |
| UPC | Not Available |
| GTIN | Not Available |
| Transmission Type | Allison LCT1000 Stage 1 |
| Drivetrain | 2WD |
| Engine Compatibility | 6.6L Duramax LLY |
| Model Years | 2004.5 - 2005 |
| Horsepower Rating | Moderate Increase Over Stock |
| Torque Capacity | Improved Over Stock |
| Shipping Weight | Approximately 400 lbs |
| Shipping Method | Freight (Core Charge Applies) |
| Warranty | 5 Year / 500,000 Mile Limited Warranty |
| California Prop 65 | WARNING: Cancer and Reproductive Harm – www.P65Warnings.ca.gov |
