Patent for 1) a mechanism preventing the Caterpillar tractor's driving element from becoming clogged with mud; 2) a mechanism to regulate the force put on the wheels in relation to the weight of the tractor's load; 3) a mechanism to allow this regulation of force in relation the weight of the tractor's load to be manually adjustable; 4) a construction improvement to allow the tractor to be turned in a relatively short radius, including illustrations.