SunCoast GMAX-CAT4 4WD Transmission | 2006-2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LBZ

Features:

• Custom clutch packs for improved performance
• Billet input, intermediate, and output shafts
• Reinforced billet flexplate for durability
• Triple disc billet torque converter
• Recalibrated valve body for better shifting
• Upgraded billet C2 clutch hub
• Billet P2 planetary gear for strength
• SunCoast custom overhaul and gasket kits
• Heavy-duty internal wiring harness
• Enhanced filtration with Filter Loc system
• Includes pan, gasket, and dual filters
• Engineered for high-torque diesel applications

Power Through Any Job Without Thinking Twice

When you're putting serious power down in your 2006-2007 Silverado or Sierra 2500HD/3500HD with the 6.6L Duramax LBZ, you need a transmission that can take a beating and keep performing. The SunCoast GMAX-CAT4 4WD Transmission is built for just that. This isn't some off-the-shelf rebuild, it's a purpose-built beast loaded with high-performance upgrades made to handle heavy towing, aggressive driving, and everything in between. From daily drivers that see weekend hauls to dedicated workhorses tackling steep grades and big loads, this transmission gives you peace of mind knowing you won't be left stranded. The custom clutch packs and billet components provide smooth, confident shifting even under load, while the triple disc billet torque converter helps get that torque to the wheels where it belongs. This transmission is the kind of upgrade that transforms how your truck feels on the road. It’s built for folks who expect their trucks to perform just as hard as they do.

Built With The Strength You Need And Then Some

Inside the GMAX-CAT4, SunCoast has completely re-engineered the transmission’s internals to survive and thrive under high torque. It starts with billet input, intermediate, and output shafts that drastically improve strength over stock components. The billet C2 clutch hub and P2 planetary gear are built to take on the added stress that comes with performance tuning and towing heavy. A recalibrated valve body delivers refined, responsive shifts that adapt to different driving demands, offering both smoother performance and increased reliability. The transmission also includes SunCoast’s custom clutch packs, custom steels, and billet plates for increased friction durability and torque handling. Added features like a new internal wiring harness and SunCoast’s Filter Loc system help ensure long-term dependability and cleaner operation. This unit is topped off with a billet flexplate and triple disc billet converter, key upgrades for any serious diesel builder looking to prevent common failure points under load. From the pan to the flexplate, every detail has been thought through to support the power your Duramax is capable of putting out.

Fits: 2006, 2007 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LBZ

Notes:

• Built specifically for 2006-2007 GM 2500HD/3500HD 6.6L Duramax LBZ
• Designed for trucks used in heavy towing, performance, or off-road applications
• Transmission ships fully assembled and ready for installation
• SunCoast recommends professional installation for optimal performance
• Transmission includes upgraded internals to handle increased horsepower and torque
• A $500 shipping surcharge will be added at checkout
• Core return may be required, check return policy and timeline
• Tested and calibrated for improved shift quality and reliability
• Compatible only with 4WD configurations, not suitable for 2WD models
• Built using all new and custom SunCoast components, not remanufactured
• Recommended to pair with tuned or modified Duramax engines for maximum benefit
• Includes billet torque converter and upgraded shafts as standard equipment