Level 3 Rebuild Kit for 6L80 Transmission

The Circle D CDTL3PK/80 Level 3 Performance Rebuild Kit is designed to significantly enhance the strength, fatigue resistance, and long-term reliability of the GM 6L80 automatic transmission, particularly under extreme torque and temperature conditions. A key component is the 104680-45 one-piece billet intermediate shaft, forged from 300M billet steel. This design eliminates common failure points found in factory multi-piece shafts and doubles the oil flow to the 4-5-6 clutch pack, which improves heat management and extends clutch life. This shaft is designed to work with 45-tooth clutch plates and features a damper-less design to reduce internal friction and rotational mass for smoother shifts and quicker response. The kit includes several enhanced clutch packs: the 4-5-6 clutch kit (CDT456L3/80) with Alto G3® clutches and Hi-Per Blue® pistons, offering 50% more apply area than stock. The 3-5-R clutch kit (CDT35RL3/80) also provides 50% more clutch apply area. Additionally, the kit features 2-6 (CDT26L3/80) and 1-2-3-4 (CDT1234L3/80) clutch kits, as well as a low-reverse clutch kit (CDTLRL3/80), all utilizing durable friction materials like BorgWarner® High-Energy and Hi-Per Blue® pistons for superior thermal and chemical resistance. Installation of this kit requires professional transmission tools and should be performed by a qualified builder familiar with GM 6L80 units. Proper ECM/TCM tuning is mandatory, as the 6L80 is a torque-based shift unit; inaccurate torque signal calibration can lead to premature clutch failure and void warranty coverage. We strongly recommend installing a stacked-plate auxiliary transmission cooler rated at 25,000 GVW to maintain operating temperatures at or below 180°F for optimal performance and longevity. Circle D Transmission rebuild kits carry a 1-year, parts-only warranty against manufacturer defects. There is no warranty for broken parts such as twisted splines, broken shafts, or broken planetaries. The warranty does not cover issues arising from improper installation, tuning, misapplication, alteration, excessive power, accidents, or neglect. Consequential and incidental damages are expressly excluded.