ATP B-239 Transmission Filter and Gasket Kit for GM 6L80 6-Speed (Silverado, Sierra, Tahoe, Yukon, Escalade)

The 6L80 six-speed is behind half the GM trucks and SUVs on the road, and the single most important thing you can do to keep one alive is change the fluid and filter on schedule. Skip it and the fine clutch material circulating in that fluid grinds down the pump, the valve body, and the clutches until the transmission is done. This ATP B-239 kit is the service part that job calls for: the correct spin-on style pan filter plus the pan gasket, so you refresh the filter and reseal the pan in one shot.

ATP builds the filter to OE levels of filtration and flow, so it traps the debris the fluid picks up without starving the pump. That flow spec matters on the 6L80, since a restrictive off-brand filter can drop line pressure and bring on the very shift problems you are trying to prevent. The included gasket is a reusable style that replaces the aged, hardened original and is designed to keep the pan from weeping fluid down the case after the service.

The kit covers the GM 6L80 heavy-duty six-speed found in the Silverado, Sierra, Tahoe, Suburban, Yukon, Avalanche, Camaro, and Escalade, among others. Fitment shifted across the years and pan depths, so confirm your year, make, model, and engine before you order. Do this service every 45,000 to 60,000 miles, or sooner on a truck that tows, and the 6L80 will go a long way past the trucks that never got it.