The Allis Chalmers 405 is a riding lawn mower produced from 1975 to 1979 in Port Washington, Wisconsin, USA. It features a 5 hp Briggs & Stratton 204cc 1-cylinder gasoline engine with manual recoil or optional electric start. The mower has a 2-speed belt-driven gear transmission with 2 forward and 1 reverse gears. It rides on lawn/turf tires sized 4.10/3.50x4 front and 16.00/6.50x8 rear, with a wheelbase of 41.5 inches. The 405 includes a 26-inch mid-mount mower deck with adjustable cutting height from 1.5 to 3.75 inches. It has two-wheel drive, manual steering, and an open operator station. The original price was $681 in 1979.