Frictions, steel plates, pan filter, gaskets and seals to overhaul a GM 4L80E or 4L85E from 1991 up in one box, for HD trucks, vans and Suburbans.
If your 2500 or 3500 Silverado or Sierra, Suburban 2500, Express or Savana van, or Hummer H1 has started flaring on the 2-3 shift, slipping into overdrive with a trailer behind it, or dumping black fluid full of clutch lining onto the drain pan, the 4L80E inside needs an overhaul. This kit puts the wear parts for that job in one box: friction plates, steel plates, the pan filter, the pan gasket, valve body and case gaskets, the front pump and output seals, piston seals, sealing rings and O-rings. It is listed for the GM 4L80E and the 4L85E from 1991 on, and it ships at 13.6 lb.
The 4L80E is essentially a Turbo 400 geartrain with an overdrive planetary added in front and the computer controlling line pressure. Every gear change is a clutch pack or band being clamped by oil pressure: the overrun, forward, direct, intermediate and overdrive clutches each stack frictions against steels, and each piston and drum is sealed by rubber and Teflon-style rings. When a pack slips, the heat glazes its frictions, blues its steels and hardens the seals around it, and the debris travels through the pump and valve body. Replacing frictions and steels together, rather than frictions alone, gives you flat, clean plates to set clearance against. The new filter matters just as much: running a fresh unit through an old filter loaded with the previous failure is how rebuilds come back.
Not every slipping 4L80E needs plates. A worn actuator feed limit bore in the valve body drops solenoid feed and line pressure and can set solenoid and ratio codes that look like a failed unit. Before you commit, check line pressure in each range, pull the pan and read what is on the magnet, and scan for a pattern of codes. Clutch lining and burnt fluid mean an overhaul; clean fluid with low pressure and solenoid codes points at the valve body. Our 4L80E common problems and fixes guide walks through telling these apart, and the high-mileage service checklist covers the other wear points on a tired unit.
This kit is listed for the 4L80E and 4L85E from 1991 and later. GM changed hard parts within that run, most notably in 1997 when cooler return oil was rerouted to lubricate the center of the geartrain, and pan depth also varies between applications. Read the ID tag on the case, compare plate counts and thicknesses against what comes out of your unit during teardown, and hold the new filter next to the old one to confirm height and neck length before you install it. If you are not sure, send us your year and VIN and we will check it before it ships. All other parts for this transmission are on our 4L80E parts page.
Inspect the hard parts first, because this kit does not include bushings, bands, solenoids, drums, the sun shell, the pump or the valve body. Soak every new friction in ATF before it goes in, set clearance on each pack as you stack it, and air check every clutch and servo before the valve body goes on. While the overdrive section is apart, look closely at the roller clutch; a worn unit is replaced with a 4L80E sprag clutch, and molded pistons such as the Hi-Per Blue 34088 piston kit are worth considering if your originals leak. Seat the filter fully into the pump bore after checking that the old filter seal did not stay behind, torque the pan bolts evenly (GM lists 18 lb-ft for pan to case), and fill with licensed DEXRON VI, checking the level hot. After the first few hundred miles, a second filter and gasket kit catches the break-in debris. Our 4L80E filter and pan service guide covers the pan job step by step.
| Fits | GM 4L80E and 4L85E, 1991-up |
| Includes | Friction plates, steel plates, pan filter, pan gasket, valve body and case gaskets, seals, sealing rings, O-rings |
| Not included | Bushings, bands, solenoids, hard parts |
| Weight | 13.6 lb |
| Condition | New |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Yes. It is listed for both the GM 4L80E and 4L85E from 1991 on. Confirm plate counts against your teardown, since the 4L85E and some late 4L80E applications use different pack stack-ups.
Bushings, bands, solenoids and hard parts such as drums, the pump, the sun shell and the valve body are not included. Inspect those during teardown and order replacements separately.
Use licensed DEXRON VI ATF. A pan-off service takes about 7.7 quarts, while a dry unit and converter hold roughly 13.5 quarts total, so check the level hot after the first drive.
That pattern usually points at the overdrive roller clutch, which holds alone in first through third in the D range. The kit covers the clutch packs, but the roller clutch is a separate part you should inspect and replace if worn.
The kit is listed with the deep pan filter. Measure your pan and compare the new filter height and neck to the old one before installing, because a mismatched filter can starve the pump.
