4L80E Shift Kit 1991-2009, new and ready to install. Fits the 4L80E. Ships fast from the USA.
A 1991-2009 Chevrolet or GMC 2500 or 3500 pickup, Suburban 2500, Express or Savana van, or Hummer H1 with the 4L80E usually tells you it needs this kit the same way: the 2-3 shift gets long and mushy when the truck is loaded, the direct clutch comes out black at teardown, or the computer starts logging gear ratio codes. This listing is a new TransGo SK 4L80E valve body repair kit, cataloged here for 1991-2009 vehicles. It is the standard TransGo SHIFT KIT for the 4L80E and 4L85E, the same kit that rebuild suppliers stock as T34165E or K34908E.
The 4L80E is a hydraulic transmission with electronic control. The computer sets line pressure through the pressure control (EPC) solenoid, and the boost valve in the pump multiplies that signal into the pressure that squeezes the clutches. TransGo calls the boost valve assembly notorious for wear. When it wears one way, pressure rise falls short and you get a soft 2-3 shift and a cooked direct clutch. When it wears the other way, boost pressure runs away and can break the case, the direct drum and the piston.
The SK kit replaces that weak point with a hardened, wide land, self-cleaning boost valve and bushing, adds an EPC boost relief valve so pressure cannot climb past a safe limit, and revises valve body, case and pump circuits to work with a modest line pressure increase. The goal is short, clean shifts that do not slip, not a neck-snapping race calibration.
Those codes do not always mean a hydraulic problem. GM's diagnostic data for the 4L80E links P0751 and P0756 to stuck shift patterns that a failed shift solenoid or a broken pass-through connector produce just as well, so check solenoid resistance and the harness first using our 4L80E shift solenoid symptoms guide. If the shifts are slow and soft rather than missing gears, the Silverado 2500 shift problems guide covers pressure checks and what a tired boost valve looks like on a gauge. A shift kit will not bring back a clutch pack that is already burned.
This listing covers the 4L80E from 1991 through 2009. TransGo itself catalogs the SK 4L80E for 1991-2013 4L80E and 4L85E units, so later trucks are covered by the manufacturer too. A quick way to confirm you have a 4L80E is the pan: it uses 17 bolts. Valve body castings, solenoids and accumulator parts changed over the years, so follow the instruction steps that apply to your year, and if you are unsure, send us your year and VIN before ordering. Everything else for this unit is in the 4L80E parts collection.
| Fits | 4L80E 1991-2009 |
| Part type | Shift Kit |
| Condition | New |
| Brand | TransGo |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. The listing covers 1991-2009 4L80E units, and the 2008 Express and Savana 2500/3500 used the 4L80E. Count the pan bolts (17) to confirm, or send us the VIN.
Yes. TransGo's own catalog lists the SK 4L80E under distributor numbers such as T34165E and K34908E. It is the standard SHIFT KIT, not the HD2 performance kit.
Part of the work is at the valve body, but the kit also includes pump and case parts and some drilling. Most installers do it during a rebuild. Read the instructions before deciding on an in-truck install.
Not if the direct clutch is already burned. The kit stops the pressure problems that burn it, but burned frictions have to be replaced first.
Use DEXRON-VI. GM lists it for these trucks, and it replaces the older DEXRON-III spec. Check the level hot and do not overfill.
