SunCoast GMAX-CAT1-LML-1116-4WD Category 1 500HP Allison Transmission with Converter | 2011-2016 Silverado/Sierra 2500HD/3500HD 6.6L

Features:

• Exclusive C1, C2, C3, and C4 frictions for enhanced durability
• Eliminates weak OEM components for better longevity
• Ensures clean, efficient fluid flow
• Premium sealing for leak-free performance
• Secure fitment and easy maintenance

Unmatched Performance for Your Allison 1000

The SunCoast Category 1 500HP Allison Transmission is the ultimate upgrade for 2011-2016 GM 6.6L Duramax owners looking for reliability, power, and efficiency. Whether you're towing heavy loads, competing in sled pulls, or just want a stronger, more capable transmission, this SunCoast unit is engineered to handle up to 500HP with ease. By using industry-leading friction materials, precision machining, and innovative design, SunCoast has developed a transmission that outperforms the stock Allison in every way, ensuring you get smooth, consistent shifts and extended transmission life even under the most demanding conditions.

Engineered for Strength, Durability, and Efficiency

SunCoast has taken the stock Allison 1000 and reinvented it for superior performance. This transmission features exclusive C1, C2, C3, and C4 Alto carbonite frictions and Raybestos SCZ frictions, designed without center slots to improve heat retention and oil flow. Redesigned apply pistons with improved rubber compounds allow for better heat resistance, while the custom apply plate ensures more even lubrication, preventing premature clutch failure. SunCoast also includes an exclusive smart trim/clutch control valve, a new internal wiring harness, and a complete valve body calibration kit, eliminating weak points found in the factory unit. Every component is precision-machined and designed for a hassle-free installation, making this the perfect drop-in upgrade for your 6.6L Duramax-powered truck.

High-Performance Billet Torque Converter – Maximum Power Transfer

Included with this transmission is a SunCoast Category 1 Torque Converter, a massive improvement over the stock unit. Featuring a billet construction and triple-disc design, this torque converter offers improved lockup, increased efficiency, and superior torque transfer. The waffle-patterned friction material helps retain oil for better cooling, and the precision CNC-machined apply piston eliminates deflection under load. Whether you're launching off the line or hauling heavy trailers up steep grades, this converter maximizes power delivery while reducing slip, giving you smoother, stronger engagement and long-lasting performance.

Vehicle Fitment: 2011-2016 GM 6.6L Duramax

Notes:

• $2,350 core charge applies.