The manual shift shafts in GM TH400 units become corroded in harsh environments and are not suitable for reuse, especially in remanufacturing. The Sonnax manual shift shaft kit 38511-05K is a direct replacement designed specifically to match the TH400 shaft geometry, which minimizes the amount of shift linkage adjustment necessary. The Sonnax manual shift shaft and fasteners have been yellow zinc plated to maximize corrosion resistance from road salt and other environmental contaminates. The flange face of the nuts is serrated for better holding capacity. TH400 specific design minimizes amount of shift linkage adjustment necessary Cost effective solution to OE late model manual shift shaft Manual shift shaft and flange nuts are zinc plated for corrosion resistance Flange of nuts is serrated for better holding. Contents Manual Shift Shaft Metric Flange Nuts (2)