124740-TL30 Pressure Switch Install Tool Kit GM 6L80E 6L90E

When a GM six-speed drops into limp mode or bangs the 1-2 and 2-3 shifts, the cause is usually the pressure switch assembly inside the TEHCM, the transmission control-and-solenoid module bolted to the valve body. The thin laminate discs that seal each pressure switch crack and leak with age, so the module can no longer read line pressure correctly. This kit rebuilds those switches instead of buying a whole TEHCM.

It fits the GM 6L45, 6L50, 6L80 and 6L90 rear-wheel-drive units and the first-generation 6T70 and 6T75 transverse units found in the Silverado, Sierra, Camaro, Traverse, Enclave, Acadia and LaCrosse. It works with the F 124740-30K service pack.

The set holds everything the job needs: a pusher piston, a seal plunger, a seal installer and a laminate installation tool, plus five rubber seals and five laminate discs, enough to rebuild one TEHCM. You drop the piston into the bore first, seat the seal with the plunger, then set the laminate disc flat with the installer foot, working it around 360 degrees so it does not fold or catch.

Done on the bench it is a couple-hour job that saves the cost of a new module and clears the rough-shift and pressure-switch codes for good. Keep a set of picks handy to lift the old discs out of the bores.