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

The early GM 6L80E and 6L90E valve bodies have known circuit weaknesses that show up as a hard 1-2 bump, lazy reverse and drive engagement once the transmission is hot, and pump volume that bleeds off through the compensator and exhaust circuits. GM addressed a lot of this on the 2014-up Gen3 units with revised castings and separator plates. This Superior/TransLab STL-6L80E kit brings those Gen3 fixes to any Gen1 or Gen2 6L80/6L90 valve body without buying an updated OE plate or casting.

The kit adds the #8 check ball and the low-reverse clutch exhaust control feature, and uses a patent-pending flow-limited compensator circuit that keeps the compensator and exhaust backfill circuits from bleeding out. That is what restores firm, consistent reverse and drive engagement when the fluid is at operating temperature instead of the delayed, mushy feel a worn Gen1 body gives you. The corrected compensator valve and calibrated springs are what deliver the smooth no-bump 1-2 shift.

It ships with the corrected no-stick select valves, end plugs and calibrated springs. These are drop-in real-steel valves and sleeves that do not require reaming the bores, so a builder can install them without a dedicated reamer setup. Fits 6L80E and 6L90E units. For a complete job on 2014-up 6L80 and 2016-up 8L90 applications, pair it with the STL010 cooler-flow system and the STL012 pump upgrade. Ships from the USA.