The High Horsepower Tractor (HHT) Series 4WD was created to respond to growing agricultural operations that have more acres and require more power. Engineered from the ground up using heavy-duty components, the HHT Series 4WD is available in 435, 485, 535 and 575 hp. The frame is manufactured from thick steel plate to ensure structural integrity, even under extreme conditions. Outboard planetary axles with a new 24 bolt pattern and standard drum duals ensure power is efficiently transferred to the ground. The main bearing at the articulation point is now 60% larger (than on the previous model range) to reduce stress and extend life.