Hapco Smooth Shift - Transmission Repair minimizes transmission slip, clatter, and reluctance. This product is designed to swiftly remove sticky gum and varnish buildup from friction surfaces. Slick Shift's cleaning and lubricating characteristics aid in the restoration of quick, reliable gear changing and smooth acceleration. To Get the Best Results: When gum/varnish accumulation is detected, add one 16-ounce container of Slick Shift straight to the transmission reservoir. (Any slippage or unexpected acceleration might indicate minimal varnish accumulation.) Drive for at least 30 minutes to completely clean the gearbox. When the gum and varnish have been removed and the performance has been restored, the filter and fluid should be replaced every 50 to 100 miles. All transmission fluids are compatible.