B&M 70365 Transpak Shift Recalibration Kit for GM 4L60E

The 4L60E leaves the factory with soft, slow shifts and a torque converter clutch that applies too gently, and that slack is exactly what wears the clutches and glazes the TCC over time. B&M's Transpak reworks the shift timing and line pressure inside the valve body so every apply happens with a firm, deliberate stroke instead of dragging through the change.

The kit is really two calibrations in one box. Stage 1 is the heavy-duty tune for trucks, towing, and daily drivers that want firmer shifts and cooler-running clutches without feeling harsh. Stage 2 is the high-performance street tune, with more aggressive full-throttle shifts for a truck or car that sees hard use. You pick the stage that matches how the vehicle is driven and build the kit that way.

You install it with the transmission still in the vehicle, dropping the pan and working the valve body, so there is no need to pull the unit. It keeps normal automatic operation with the selector in Drive, so the truck still shifts itself around town, just cleaner and firmer. It fits the GM 4L60E behind small blocks in the Silverado, Sierra, Tahoe, Suburban, Yukon, Camaro, and the rest of the GM rear-drive lineup, and is backed by a one-year manufacturer warranty. Ships from the USA.