4L80E Overhaul Kit 1990-96, new and ready to install. Fits the 4L80E. Ships fast from the USA.
If your early-1990s Chevy or GMC 2500 or 3500, Suburban 2500 or full-size van has a 4L80E that now slips when it gets hot, bangs into Reverse, or slides through the 2-3 shift under a load, the clutch packs and seals have probably given up together. This new overhaul kit carries the Alto brand and supplies the clutch plates and soft parts for a complete rebuild of a 1991-1996 4L80E: friction plates, steel plates, sealing rings, metal-clad seals, gaskets, O-rings and a new filter. It is labeled 1990-96 because rebuild catalogs often round the range back to 1990, but the 4L80E entered production for the 1991 model year, so think of it as a kit for the first six years of the transmission.
Each of the 4L80E's clutch packs is a stack of alternating friction and steel plates squeezed together by a piston. When the frictions wear thin or the steels warp, the pack needs more pressure to hold, and the transmission starts to slip. Sealing rings and metal-clad seals keep that pressure inside the drums and the case, so once they harden or wear grooves, even a good clutch pack cannot get the oil it needs. Replacing the plates and every seal at the same time is what lets a worn early unit hold torque again behind a 454 or a 6.5 diesel.
What this kit does not include matters just as much. There are no bands, bushings or bonded pistons in the box, so plan to measure the bushings, inspect both bands and check each piston before you order the rest of your parts.
An early 4L80E has solenoids, a harness and speed sensors that can all fake a mechanical failure. Scan for codes and look at the input and output speed readings first; our 4L80E speed sensor symptoms guide shows what a bad sensor looks like on a scan tool. Then pull the pan. Clutch material, varnish and a line pressure reading that stays low in more than one gear mean the unit needs this kit, not just a solenoid. The 4L80E common problems and fixes guide lays out the pressure test.
The kit fits the 4L80E built from 1991 through 1996 in Chevrolet and GMC trucks, Suburbans and vans. It does not fit the 1997-later center-lube units. Within the early years, two changes affect the parts you reuse. ATRA reports that GM introduced a new pressure control solenoid, shift solenoids, harness and connector in 1994. Sonnax notes that a low/reverse servo spacer kit fits 1996-later units only, so the 1996 low/reverse servo hardware differs from earlier years. Sonnax also identifies 1991-1996 valve bodies by two small holes that are missing on later bodies. If your build date falls near a changeover, send us the year and VIN and we will confirm the match. Browse the full early-unit lineup on our 4L80E parts page.
For a truck that tows, many rebuilders add a TransGo SK 4L80E shift kit while the valve body is off to firm the shifts and cut clutch slip time. On a 1994-1996 unit, replace the 1994-2003 pressure control solenoid at the same time, since a weak one lowers line pressure on brand-new clutches.
| Fits | 4L80E 1990-96 |
| Part type | Overhaul Kit |
| Condition | New |
| Brand | Alto |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Not in production trucks. The 4L80E arrived for the 1991 model year. The 1990-96 label is a catalog range, and the kit is meant for the 1991-1996 units.
No. It includes friction plates, steel plates, sealing rings, metal-clad seals, gaskets, O-rings and a filter. Inspect your bands, bushings and pistons and order those separately if they are worn.
No. GM changed to center-gearbox lubrication in 1997 and redesigned several internal parts, so a 1997-later unit needs a later kit.
1994 brought a new pressure control solenoid, shift solenoids, harness and connector. Replace solenoids with the matching 1994-later parts; a 1991-1993 style pressure control solenoid in a later unit can cause high line pressure.
Use Dexron VI, which GM now specifies for the 4L80E and which replaces the older Dexron grades. Set the final level with the fluid at operating temperature.
