4L80E Master Rebuild Kit 1990-96, new and ready to install. Fits the 4L80E. Ships fast from the USA.
Early 4L80E transmissions are still working behind big-block and diesel GM trucks, Suburbans and full-size vans from the first half of the 1990s, and many of them are now on their second or third round of wear. This new master rebuild kit is listed for the 1990-96 production run: the first-generation 4L80E, before GM moved to center lubrication in 1997. If your early truck slips under load, burns fluid, or has a pan full of clutch material, this kit supplies the frictions, steels, seals and gaskets for a complete overhaul.
The 4L80E arrived for the 1991 model year as GM's electronic replacement for the TH400, adding an overdrive section and computer-controlled shifts to the same tough three-speed core. On the early units, cooler return oil still feeds lube through the pump, the arrangement Transmission Digest notes GM abandoned in 1997 when it relocated the cooler return to the center support. A master kit renews every clutch pack and seal in that early layout, so the rebuilt transmission holds line pressure and applies each clutch with full clamping force. It does not replace hard parts, which is why the inspection steps below matter on a unit this old.
Rule out the electrical side first. ATRA's Technical Bulletin 266 explains that 1994 brought a new pressure control solenoid, new shift solenoids, a new harness and connector and new trouble codes, so a 1991-93 truck and a 1994-96 truck diagnose differently. A wrong or failing pressure control solenoid can cause harsh shifts or slipping on its own; our 4L80E pressure control solenoid guide covers how to test it. If the solenoids check out and a pressure test is good but the unit still slips, the clutches are done. Our 4L80E rebuild cost guide shows what a complete job usually includes.
This kit is listed for 1990-96 4L80E units. Production of the 4L80E began for the 1991 model year, so a 1990 date generally means an early-build unit; identify yours by its transmission ID tag. Inside this range there are real differences: Sonnax notes the 1991 valve body used a screw-in temperature sensor that moved into the internal harness for 1992-96, and Sonnax's build-guide data shows 1995-and-earlier units use an adjustable low/reverse servo pin where 1996 units use a servo spacer. The soft parts are shared across these years, but send us your year and VIN if you have any doubt. For 1997 and later units, use the 1997-2011 master kit, and see all options on our 4L80E parts page.
An early 4L80E has usually seen a lot of heat, so inspect every drum, bushing and sprag before reassembly. Check the clutch drums for scoring and spline wear, and if your module is damaged, the 1989-1995 clutch module matches this era. Replace worn bushings, measure end play, and set clutch clearances to spec. Do not mix a Bosch-style pressure control solenoid into a 1994-96 unit: ATRA warns that the silver 1991-93 Bosch part removes the balance oil the later black Holley design depends on, which causes high line pressure. While the pan is off, inspect the internal harness and replace it with the 1991-2003 internal harness if the insulation has gone brittle. Soak the frictions, air-check each circuit, flush the cooler, install a new converter and fill with Dexron VI, which is back-serviceable for the Dexron III these units shipped with.
| Fits | 4L80E 1990-96 |
| Part type | Master Rebuild Kit |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No, it is listed for 1990-96. GM moved the 4L80E to a center-lube design in 1997 and changed several internal parts, so 1997 and later units should use a 1997-up master kit.
The 1994 changes were mostly electrical: new pressure control solenoid, shift solenoids, harness and connector. The clutch and seal parts in this kit cover the range, but make sure the correct black Holley-style pressure control solenoid goes back in a 1994-96 unit.
The 4L80E was introduced for the 1991 model year, so a 1990 date usually refers to early production. Go by the transmission ID tag and the vehicle VIN rather than the calendar year.
Bushings, the torque converter, any scored drums, a worn sprag or roller clutch, and the internal harness if it is brittle. A shift kit is a common addition on a high-mileage early unit.
These units originally used Dexron III. Dexron VI is back-serviceable for Dexron III applications and is the fluid to use today.
