Seals the 6L80/6L90 3-5-Reverse and 1-2-3-4 clutch drum so you can air-test each apply circuit and pinpoint the hairline cracks and leaking piston seals that cause slipping and no-reverse.
The 3-5-Reverse and 1-2-3-4 clutch drums in the GM 6L80 and 6L90 are a known failure point. Both drums crack around the piston bore and hub, and the cracks are usually too fine to see with the drum in your hand. A cracked drum bleeds off apply pressure, and the result is a slipping 3-5-Reverse clutch, a harsh or missing reverse, or a 1-2-3-4 clutch that burns up again a few thousand miles after a rebuild. Guessing means tearing the unit back down.
This tester is a CNC-machined 6061 aluminum plug that seals the drum so you can pressurize the apply circuits one at a time. Drop the tool into the drum, put an air nozzle to each marked port, and blow compressed air in. A drum that holds pressure is good; one that hisses or will not build pressure has a crack in the casting or a blown piston lip seal. You find the bad drum on the bench instead of after the transmission is back in the truck.
It fits 2006-and-up GM applications running the 6L80 and 6L90 six-speed: Silverado, Sierra, Tahoe, Suburban, Yukon, Escalade, Camaro, and the Cadillac CTS and STS, covering both the 1-2-3-4 and 3-5-Reverse drums. Machined from solid billet so the sealing faces stay true, and light enough to keep on the bench next to your air gun. Ships from the USA.
| Fits | GM 6L80 and 6L90 (2006-up Chevy, GMC, Cadillac cars and trucks) |
| Tests | 1-2-3-4 clutch drum and 3-5-Reverse clutch drum apply circuits |
| Material | CNC-machined 6061 aluminum billet |
| Method | Seals the drum for compressed-air leak and crack testing at each port |
| Weight | 2.4 lb |
| Part number | WCH003 |
