Description Cap, front wheel, EXACT of ORGINAL. 1.970" thread O.D., 1.670" high. Tractors: 9N, 2N, 8N, NAA, 501, 600, 700, 800, 900 (1939-1957). This item is a suitable alternative for the following: 2N1139B, 957E1139WF, 957E1139, 81717282, 723355, 191142M2, 191142M1, 1884289M1, 180009M2, 180009M1