Complete 6L80 and 6L90 overhaul kit with 30 steel plates, 35 frictions, gaskets, seals and a new filter for GM six-speed truck and car builds.
Most 6L80 rebuild kits stop at frictions and seals, and that is where a lot of comeback jobs start. When a Silverado, Sierra, Tahoe, Suburban, Escalade or Camaro has been slipping long enough to cook a clutch pack, the steel plates in that pack are usually blued or warped too. This kit puts 30 new steel plates and 35 new friction plates in the same box as the pan filter and the overhaul gasket and seal set, so every pack in the transmission goes back together with fresh surfaces on both sides.
Each clutch pack in the 6L80 is an alternating stack: a friction plate splined to one member, a steel plate splined to the other, repeated until the piston can squeeze the stack and lock the two together. The 3-5-Reverse and 4-5-6 packs in the input housing work the hardest, because they apply and release on almost every upshift and downshift. When those packs slip, the heat goes into the steels first. A heat-checked or dished steel no longer presents a flat face, so a new friction riding against it glazes quickly and the slip returns. Replacing the steels with the frictions is what makes the rebuild last.
A 2-3 flare on a cold 6L80 is not always worn clutches. GM has documented a cold-weather 2-3 slip caused by air trapped in the 3-5-R clutch circuit, which is cured by a fluid procedure rather than parts. If the slip is there hot and cold and the fluid looks burnt, then the packs are the likely cause. Read our 6L80 Camaro common problems guide for that trapped-air bulletin and the steps around it, and the 6L80 common problems guide for the full test order.
The kit is listed for the GM 6L80, 6L80E, 6L90 and 6L90E in 2007-2014 Silverado and Sierra 1500, 6L90 Silverado and Sierra 2500HD and 3500HD, Tahoe, Suburban, Yukon and Yukon XL, 2007-2015 Escalade and ESV, Express and Savana 2500 and 3500 vans, the 2010-up Camaro, the 2006-up Corvette, the 2006-2011 STS and the CTS-V. It cross-references the KP33900JBX, KP33900JAX, K-135900DX-AFT, 195804X, 34352KIT, 24236931, 24236933, 135710D, 34661P and 195940 kit numbers. Because the 6L90 runs more plates in some packs than the 6L80, count each pack as you take it apart and set the old plates next to the new ones before you build. Confirm the RPO code on the vehicle (MYC for 6L80, MYD for 6L90), or send us the year and VIN and we will check it against the list. Everything else we carry for this unit is on the 6L80 transmission parts page.
Soak every friction in clean Dexron VI before stacking. Build one pack at a time, then measure the clearance with the pack compressed and correct it with the selective plate to the factory or ATSG figure; new steels and frictions change the stack height, so do not assume the old clearance carries over. Pistons and bushings are not in this kit, so inspect the piston bonding and every bushing during teardown and source what you need. The 6L80E clutch drum removal and installation tool saves the input housing when you pull and reinstall it. This is a good time to replace the pan with a 6L80 oil pan kit with drain plug, since the factory pan has no drain. Replace the filter neck seal in the case with the filter, fill with Dexron VI only, then reset the adapts and run a relearn drive.
| Transmission | |
| Steel plates | |
| Friction plates | |
| Includes | |
| Interchange | |
| Not included | |
| Shipping weight |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
A slipping pack overheats its steels. Reusing blued or warped steels against new frictions glazes the new lining and the slip returns. Having all 30 steels in the box means every pack goes together with flat, clean surfaces.
No. It includes steels, frictions, the pan filter, overhaul gaskets, O-rings, sealing rings and washers. Pistons, bushings, the pump, the valve body, the torque converter and fluid are not included.
The kit is listed for both. The 6L90 uses more plates in some packs, so count each pack during teardown and lay the old plates beside the new ones before building. Confirm your RPO code, MYC for 6L80 or MYD for 6L90.
Maybe not. GM has a bulletin for a cold 2-3 flare caused by trapped air in the 3-5-R circuit that is fixed with a fluid procedure. If the slip happens hot as well and the fluid is burnt, the clutch packs are the more likely cause.
Fill with Dexron VI, check level at the case check plug at operating temperature, then reset the transmission adapts with a scan tool and complete a relearn drive.
