Superior STL-6L80E 6L80E/6L90E Valve Body Upgrade Kit

The Superior STL-6L80E is a TransLab-engineered correction and upgrade kit for the GM 6L80E and 6L90E six-speed valve body. It retro-fits GEN1 and GEN2 castings to the later GEN3 (2014-up) circuit features without buying an updated OE separator plate or a new casting, so you fix the known valve body faults on the body you already have. It fits the 2006-up 6L80/6L90 used in the Silverado, Sierra, Tahoe, Yukon, Suburban, Escalade, Camaro, Corvette, CTS, and the Express and Savana vans.

The kit adds the #8 check ball and a Low-Reverse clutch circuit exhaust control feature, plus a patent-pending FLOW-LIMITED compensator valve and circuit. That restores integrity to the compensator and exhaust backfill circuits, which limits the loss of pump volume (the bleed-out that starves line pressure) and improves Reverse and Drive engagement, especially once the fluid is hot. The corrected NO-STICK select valves, end plugs, and calibrated springs clean up the bumped or flared 1-2 shift.

On the bench, drop the pan, pull the valve body, and disassemble it to install the compensator valve, select valves, springs, and check ball per the instructions. The valves are NO-REAM drop-in real-steel valves and sleeves, so there is no machining or reaming of the aluminum bores. Reassemble, reinstall the valve body, and finish with a fresh filter and Dexron VI. Combine it with the STL012 6L pump upgrade, and on 2014-up 6L80 or 2016-up 8L90 add the STL010 Sure-Cool cooler-flow kit, for complete protection. Ships from the USA.