GM 4L80E Performance Transmission Upgrades

Originally found in 3/4- and 1-ton trucks, the 4L80E and higher-torque 4L85E transmissions share gear ratios with the 3-speed TH400, but add the 4th Gear Overdrive which is popular for high-horsepower street cars. Sonnax upgrades take reliability of these versatile units to the next level for optimum performance in any heavy-duty, street and extreme racing vehicle.

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4L80E Performance & Heavy-Duty Transmission Build Guides

From hardworking trucks to extreme street/strip race vehicles, it’s easy to add unmatched reliability to vehicles of any power level with Sonnax. Check out these handy build guides to get maximum results out of your rebuild.

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View High Performance Build - Under 1,000HP

View High Performance Build - Over 1,000HP

Sonnax 4L80E Build Guides

See What's Inside the Sonnax 4L80E Performance Pack

Watch this video to get a full breakdown of everything you get in the most comprehensive transmission upgrade kit on the market for GM 4L80E and 4L85E units: Sonnax Performance Pack HP-4L80E-01. This unique kit includes components to precisely recalibrate pressures and shift accumulation PLUS heavy duty parts to repair damage, prevent future wear and improve reliability. Top builds for maximizing work/sport vehicle performance and durability start here!

Sonnax high performance products meet the toughest challenges faced by hard-working, daily-use drivetrains as well as racing units going all-out on the street or track.

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