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Circle D Transmission is ready to turn your 8L90 into a performance beast. We’ve been a leader in the transmission industry since 1976. Our continued development in custom modifications and billet upgrades makes your choice an easy one. Please select one of the options below for more information.
For vehicle owners comparing rebuild options, we proudly offer Raybestos rebuilds designed to deliver unmatched durability and precision. Known as a trusted manufacturer in the industry, Raybestos performance clutches and components help reduce brake fade, minimize heat, and ensure smoother gear transitions on both the track and the road. Whether you’re searching for enhanced towing capability, improved acceleration, or greater reliability under high horsepower conditions, our Raybestos rebuild packages provide a proven solution that outperforms stock assemblies.
Drivers who search for high‑quality 8L90 upgrades often discover that Circle D Transmission stands apart for its expertise and commitment to excellence. By combining Raybestos rebuilds with our precision billet upgrades, we deliver a complete performance package engineered to maximize power, durability, and driving confidence. Every component we install is carefully manufactured to meet or exceed OEM standards, ensuring your 8L90 transmission performs flawlessly whether you’re daily commuting, towing heavy loads, or pushing limits on the open road.
Why choose Circle D for your 8L90 transmission rebuild? The answer is simple: we’ll get the job done right. We combine decades of knowledge and experience with a passion for new technology, development, and research, making us leaders and innovators in the transmission industry. Our team has specialized in Ford and GM rear-wheel drive high performance transmissions since 1976. We’ll get your horsepower to the pavement where it belongs, whether it’s for a custom show vehicle or street and strip.
Transmission rebuilds aren’t just our business—they’re also our passion. We love what we do and it shows in our service. Even before you submit your order for a 8L90 transmission rebuild, our experts are available to answer any questions you might have and once your transmission rebuild is complete, we’ll still be here to offer assistance.
The Circle D business has expanded over the years, from our beginnings as a two bay shop to becoming the go-to destination for Houston locals who need transmission rebuilds. These days, you’ll also find our high performance transmission parts and rebuild services for transmissions available for online purchase, allowing horsepower junkies from across the country to enjoy the same 6L80 performance rebuilds as our Houston neighbors.
As a small, family-owned business, we’re thrilled to know that our transmission rebuilds and parts are being used in vehicles near and far. Contact our team today to learn more about our 8L90 performance transmission rebuild services or fill out our performance questionnaire to start the process.
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The Crew at CDT
A Raybestos 8L90 rebuild kit is a comprehensive package designed to restore and enhance your transmission’s performance and durability. It typically includes premium friction clutch packs, steels, piston assemblies, gaskets, and seals—all manufactured by Raybestos Powertrain, a trusted name in the transmission industry. These components are engineered with advanced materials to provide superior heat resistance, reduce wear, and improve clutch holding capacity compared to stock parts. The friction materials are precision‑matched to fit perfectly within your 8L90 transmission, ensuring smoother gear engagement and longer service life. Whether you’re doing a complete rebuild or just replacing worn clutches, the Raybestos kit offers a reliable and performance‑focused solution that is a direct replacement for OEM parts and ideal for both daily drivers and high‑performance vehicles.
Raybestos friction modules, such as the GPZ or RHT series, bring significant improvements to the 8L90 transmission by enhancing clutch surface durability and reducing slippage during gear shifts. These friction components are specially formulated to handle higher heat loads and provide better resistance to wear, which is critical for maintaining consistent and smooth shifting over time. By minimizing heat buildup inside the transmission, the modules help reduce the risk of clutch fade—a common cause of rough or harsh shifting. This translates to improved transmission reliability and responsiveness, especially important for vehicle owners who use their trucks or SUVs for towing or heavy-duty applications. The superior friction material also extends the life of the transmission fluid by reducing contamination and breakdown, resulting in more efficient power transfer and a longer-lasting transmission.
Yes, combining Raybestos friction modules with Circle D’s high‑performance billet upgrades creates one of the most durable and performance-oriented 8L90 rebuild packages available. While Raybestos provides top-tier friction and clutch components, Circle D’s billet torque converters, reinforced input shafts, pressure plates, and valve bodies add strength and reliability to critical transmission parts. This synergistic combination delivers improved torque multiplication, smoother gear shifts, and enhanced overall transmission capacity, making it perfect for drivers looking to maximize horsepower and towing ability without sacrificing long-term durability. Many of our customers choose this combo for drag racing, off-roading, or heavy towing where standard parts simply don’t hold up. The package is designed as a complete solution for easy, direct replacement and is backed by expert technical support to help you get the best performance out of your rebuild.
Raybestos rebuild kits are designed with precise manufacturing tolerances, making them suitable for both experienced DIY enthusiasts and professional transmission shops. The kit comes with all the necessary components and detailed instructions for a straightforward installation process. However, due to the complexity of automatic transmission rebuilds, having the right tools and knowledge is essential to ensure proper assembly, clearances, and adjustments. When combined with Circle D Transmission’s custom tuning services and expert support, the installation process becomes more manageable, reducing the risk of errors that could affect transmission performance or longevity. For vehicle owners unfamiliar with rebuilds, we recommend professional installation to guarantee optimal results, but skilled DIYers often appreciate the quality and fitment of Raybestos parts that make the job easier and more reliable.
Choosing Raybestos rebuild parts over stock components offers several critical advantages that improve the overall transmission performance and lifespan of your 8L90. Stock clutches and friction materials are often not designed to handle increased power, heat, or towing stress beyond factory specifications, which can lead to premature wear, slipping, and harsh shifting. Raybestos parts use advanced materials and manufacturing processes that provide superior heat tolerance, improved wear resistance, and enhanced clutch holding capacity. This results in smoother shifts, better torque transfer, and a reduced chance of transmission failure in demanding driving scenarios. Whether you’re driving on the highway, towing heavy loads, or pushing your vehicle on the track, Raybestos components help maintain consistent performance and extend your transmission’s road life. Additionally, their products are rigorously tested and trusted by manufacturers and rebuilders worldwide, giving vehicle owners peace of mind that their transmission is rebuilt with quality and reliability at its core.