You have no items in your shopping cart.
Monday thru Friday 7:00 am to 5:00 pm CST
Texas - Central Time
When your vehicle’s engine delivers increased horsepower or your usage demands heavier loads, the stock 8L90 transmission can start showing its limits. Upgrading to performance parts lets you preserve reliability, durability, and efficiency under stress. Quality components, such as stronger clutches, reinforced valve elements, and upgraded torque converter options, help the transmission handle higher torque and preserve operating integrity. These enhancements aren’t just for racing; they also improve shift control, reduce slippage, and increase the system’s resistance to heat and wear.
Performance parts from trusted names like Raybestos bring material quality, precision engineering, and tested performance to your build. A properly spec’d torque converter combined with heavy-duty clutches and improved control valves ensures performance under load, better gear ratio stability, and smoother shifts. These upgrades can prolong the life of your transmission by reducing heat stress, optimizing fluid dynamics, and reinforcing weak points in the system. Investing in top-tier 8L90 components helps turn a high-stress driving environment into a reliable, repeatable system you can trust day after day.
Not necessarily. Choosing parts from respected manufacturers and matching components properly can maintain (or even improve) daily-drive reliability. The key is using quality upgrades suited to your power level, vehicle weight, and usage without overspecing in a way that stresses adjacent systems.
A higher-capacity or multi-disc converter can clamp more consistently, reduce slip, and manage heat better under load. That improves torque transfer, minimizes wasted energy, and protects transmission fluid and clutch materials from excessive wear.
In many cases yes. Upgrades may shift how the 8L90 responds to throttle, shift points, and line pressure. Tuning or adapting shift maps can help you extract the benefits of stronger parts without inducing harsh shifts or improper pressure behavior.
Premium parts cost more, but their materials, manufacturing tolerances, and durability often pay off by avoiding frequent replacements. Over time, the cost of rebuilding aftermarket or weak stock parts can eclipse the investment in better gear.
The GM 8L90 transmission is a complex 8-speed automatic used in a wide range of performance cars and trucks. Whether you’re a professional mechanic or a DIY rebuilder, having access to a complete service manual is essential. This official ATSG technical repair manual provides step-by-step instructions for inspection, disassembly, rebuilding, troubleshooting, and repair of the 8L90 transmission. FREE UPS Ground to the contiguous United States (lower 48) if purchased with a Kit. FREE USPS Priority Mail if purchased separately.
The STL010 Sure-Cool System is engineered specifically for 2016 and newer 8L90 transmissions to enhance performance, protect internal components, and maintain optimal thermal control. With features like full-time cooler flow, immediate cooler fill, and a built-in safety bypass, this system helps manage temperature, fluid quality, and shifting reliability, preserving clutches, torques, valves, and the entire transmission under demanding conditions.
FREE UPS GROUND if purchased with a Kit. FREE USPS Priority Mail if purchased separately.
The Sonnax 1-3-5-6-7 Signal Accumulator Piston Kit restores smooth, consistent hydraulic performance in GM 8L90 transmissions by eliminating fluid leaks and stabilizing line pressure. Over time, wear in the accumulator bore can cause pressure loss, erratic shifts, and converter clutch concerns. Replacing the worn components with Sonnax’s hardcoat anodized aluminum piston and O-ring sealing system helps regulate line fluid pressure, maintain proper shift control, and ensure the transmission’s clutch circuits perform as designed.
FREE UPS Ground to the contiguous United States (lower 48) if purchased with a Kit. USPS Priority Mail if purchased separately.