At the U.S. Farm Progress Show this past August, tire manufacturer Titan International and Montana farmers Welker Farms teamed up to show off the largest available ag tractor tires — mounted on a classic horsepower-leading tractor.
Welker Farms rebuilt and modified its KTTA 700 Big Bud tractor and mated it with a companion Demco grain cart, both fitted with the same Titan1400 LSW tires.
Welker Farms has a social media presence on YouTube and has documented the rebuild of the Big Bud.
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The tractor was originally a 1977 KT450 Series II model, equipped with a 19-litre, 1,150-cubic-inch Cummins engine. But when the Welkers bought the tractor it didn’t have an engine or transmission, so they implanted a newer Cummins rated at 700 horsepower mated to a heavy-duty Allison 6000 Series transmission.
As documented on Welker’s Youtube channel, the tires were so large they required modifying the original fenders on the Big Bud to accommodate them. The tractor required a new set of specially built rims to mount the tires to the 75,000-lb. Caterpillar axles.
Mounting the larger tires also meant the drawbar had to be redesigned to lower it back down to the proper height, because the new tires raised the chassis.
The Welkers also designed a mechanical PTO for the Big Bud in order to operate the grain cart.
