Drop-in shift correction kit for GM 6L80, 6L80E, 6L90 and 6L90E automatics (2007-2014) that fixes worn pressure regulator bore damage and harsh shifts.
If your Silverado, Sierra, Tahoe, Yukon, Escalade, Camaro or Corvette has a delayed or delay-then-bang engagement into Drive or Reverse, shifts that change from one day to the next, or a stack of ratio and pressure switch codes, the hydraulic circuit that sets line pressure is a prime suspect. The TransGo SK6L80 is the base repair kit for that circuit in the GM six-speed rear-wheel-drive family: 6L45, 6L50, 6L80 and 6L90. It is a restore-to-correct kit, not a firm-shift calibration.
Every clutch apply in a 6L80 starts with line pressure, and line pressure is set by the pressure regulator (PR) valve that rides in a bore in the pump. TransGo says these units often come in with a delaminating PR valve that wears that bore, which lets pressure wander. The second wear point is the solenoid regulator valve bore, which feeds the regulated supply the shift and pressure control solenoids work from. When either bore leaks, the TEHCM commands one pressure and the clutches get another.
The kit answers both without machining. It uses a hardened, precision-ground steel PR valve with longer lands at each end, designed to seal even in a pump with substantial bore wear, and to give full-time line-to-lube. A new boost valve and bushing carries a built-in EPC relief to cap damaging pressure spikes. The solenoid regulator valve is replaced with a steel valve running in its own guide insert, so it no longer depends on the worn original bore. You also get five pressure switch diaphragms and five seals to renew the TEHCM pressure switches, plus three high-temperature stator rings with expanders for early stator supports that do not use locking sealing rings.
Those codes can also come from worn clutches or a bad solenoid, so treat them as a reason to test, not proof.
Put a gauge on the mainline port on the passenger side and compare actual pressure with the EPC command on your scan tool, stepping the command up and down with bi-directional controls. Pressure that is low at idle but climbs with engine speed points at pump output; pressure that will not follow the command points at the regulator circuit this kit rebuilds. Our 6L80 harsh shift causes guide separates pressure faults from adapt and solenoid faults, and the 6L80 shift solenoid symptoms guide covers the codes that look like solenoids but are not.
Our listing covers 2007 through 2014 GM 6L45, 6L50, 6L80 and 6L90 units, and TransGo's own application reads 2006 and later. Because the kit replaces valves in the pump and valve body rather than relying on bore size, it covers most of the family, but early and late pumps and stator supports were updated over the run. Compare the parts in the box against what you pull out, or send us your year and VIN before ordering. All of our 6L80 parts are on the 6L80 collection page. If you tow heavy or make extra power, TransGo's firmer 6L80 TOW and PRO kit is the step up.
This is a bench job. The pump comes off for the PR valve, boost valve and stator rings, and the valve body and TEHCM come out for the solenoid regulator valve and pressure switch seals. Follow the TransGo instruction sheet in order and keep removed parts laid out. Most builders install it during an overhaul with a 6L80 master rebuild kit, because pressure trouble usually has already cooked a clutch pack. Refill with DEXRON-VI using the GM level check procedure, since there is no dipstick, then reset transmission adapts and drive the unit through a relearn. A new 6L80 pan with drain plug and filter makes the next fluid service far easier.
| Fits | GM 6L45, 6L50, 6L80, 6L90 series automatics, 2007-2014 |
| Kit includes | Drop-in pressure regulator valve, solenoid regulator valve assembly, EPC relief with new boost valve, high-temp HD clutch rings, (5) pressure switch repair elements |
| Fixes | Worn pressure regulator valve bore, low line pressure, leaking pump rings, blown pressure switches |
| Installation | Drop-in valves; no special tooling or machining (unit must be disassembled) |
| Mfr part number | SK6L80 |
| Brand | TransGo |
| Ships from | USA |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is a valve body and pump repair kit that restores correct line pressure control. Shift feel should return close to factory. For firmer towing and performance shifts, TransGo offers a separate TOW and PRO kit.
No. TransGo designed every valve in the kit as a drop-in, so no reaming or special tooling is required. The transmission still has to come apart to reach the pump and valve body.
Yes. TransGo lists the kit for 6L45, 6L50, 6L80 and 6L90 units from 2006 on. Our listing is shown for 2007 to 2014; send your year and VIN if you want us to confirm.
DEXRON-VI. The 6L80 has no dipstick, so set the level with the check plug procedure at the specified temperature in GM service information.
Yes. Reset transmission adapts with a capable scan tool and drive the vehicle through the adapt procedure so the TCM relearns clutch fill times with the corrected pressure.
No. It removes a common cause of clutch damage, but burned friction plates must be replaced. Pair it with a rebuild kit if the unit slips.
