Belt, Fan (ENG. SN 700000-799999 / 220000- > ). PART NO: A-72090561. Allis-Chalmers TRACTOR: 5040 Allis-Chalmers TRACTOR: 5050 (ENG. SN 700000-799999 / 220000- > ). . MODELS: Allis-Chalmers TRACTOR: 5040 Allis-Chalmers TRACTOR: 5050 (ENG. SN 700000-799999 / 220000- > ).